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I'm not inquiring about a Headspace gauge, I'm inquiring about a gauge that looks at the dimension to the shoulder of the chamber and to the shoulder of the the case. Has such ever been made?
There was formerly a Stoney Pointe case gauge, now something similar made by Hornady, which would appear to work for measuring where the shoulder is, but I am looking for a steel gauge.
CDD :cool:
I'm unsure exactly what you're looking for, but measuring a normal fired case will give the bolt face to shoulder dimension of the chamber (plus any action stretch). Nothing fancy is required - a 9mm pistol case works about as well as anything if we're looking for comparative rather than absolute dimensions. A more durable version can be made from a 1" section of 1/2" steel rod bored with an inside diameter appropriate to the cartridge neck and shoulder - but will not yield results visibly different when using a .001" caliper.
https://www.milsurps.com/images/impo...mmcasega-1.jpg
Use the same setup on a sized case to see what change has occurred during sizing. Or compare fired cases from two rifles to measure any difference in the face-shoulder dimension. A similar arrangement can be used to measure differences in action stretch at varying pressures, but it may take a good .0001", 3" jaw micrometer to register the small amounts involved.
Nobody ever worried too much about it; the rim, they thought, took care of most of the problems this would have caused with a rimless case. Of course they did have to increase the dimensions in WW1, to take care of dirty or indifferently made ammunition. Reloading, of course, was not considered (nor should it have been).
Some folks believe that they can obtain the best accuracy if the case fits the chamber tightly in addition to the headspace being tight. I can see that it might be true, but have never seen any solid data to show that it is. If anyone has, I am sure the folks here would appreciate seeing it.
From a purely functional viewpoint, of course, the position of the case shoulder in a rimmed case like the .303 or the .30-30 is pretty much irrelevant as long as it doesn't interfere with chambering.
Jim
Yes they are called “Wilson Case Gauge BUT they are for a SAAMI commercial chamber BUT they tell an interesting story, the cases rest on the shoulder for gauging purposes.
Below is the Wilson gauge with a new unfired Remington .303 case inside the gauge, as you can see Remington and Winchester do NOT know where to put the shoulder of the case and the case is a ¼ inch below where it should be.
The gauge has a slight groove milled in the top and bottom, the top represents min & max headspace and the bottom groove is min & max case length
https://www.milsurps.com/images/imported/deleted.gif
Next is a fired case in the gauge and now it is sticking above the top of the gauge, this represents how far the military chamber was reamed and lengthened to allow for dirt and mud in the chamber. The gauge is still usable with a vernier caliper but the milled groove for head space can not be used.
https://www.milsurps.com/images/impo...4/under2-1.jpg
Below in the top photo is a South African PMP surplus please note that they know where to put the shoulder of the case, this case is perfectly made and is .002 below the min headspace line on the gauge.
NOTE: the American Remington and Winchester cases average .058 on rim thickness on the cases I have, the South African PMP .303 has a rim thickness of .062 again .002 below minimum headspace as it should be.
https://www.milsurps.com/images/impo...twocases-1.jpg
Our American made .303 cases leave a lot to be desired, the are designed for a lower pressure than military standard which is approximately 45,000 CUP, our American ammunition is loaded to pressures lower than 43,000 CUP due to the older No.1 or SMLE still being used and shot (lawsuits) and these cases do not stand up well during reloading.
On the other hand Prvi Partizan cases are some of the best commercially made cases that can be used for reloading, they have thicker rims and larger base diameters than our American cases do.
https://www.milsurps.com/images/imported/deleted.gif
https://www.milsurps.com/images/imported/deleted.gif
Below base diameters of the Privi and Greek HXP cases, this is just one reason I give the Privi cases high marks.
https://www.milsurps.com/images/impo...privihxp-1.jpg
I dont have data. But I can say that it sure helps the .303 Enfields that I have to just neck size, cuts group size down alot.
Cary
[QUOTE=Edward Horton;35120]“Wilson Case Gauge"
Mr Horton:
That is precisely what I want. :thup: I've been all over the internet, and I can't find that. Can you point me to where I can get one?
I'm doing a study of relative elastic movement in actions on firing. I want to study those that are regarded as moving a bit, those that move some, and those that don't move much. I have ordered a Hornady tool already to measure cases from shoulder datum line to rear of case head, and I'd like to have case gauges and gauges to measure the distance from a datum point on the shoulder of the chamber to the boltface. I've been trying to figure out where I could put a strain gauge to get direct measurement, and can't see a place that will give me meaningful info.
CDD
L.E.Wilson is an old name in precision reloading equipment, and RCBS also makes the precision mic which reads like a micrometer.
L.E. Wilson Inc. Wilson Tools and Gages
http://www.lewilson.com/images/2009_...Mini_Final.pdf
MidwayUSA - L.E. Wilson Cartridge Headspace Gage 303 British
http://www.midwayusa.com/viewproduct...tnumber=574297
The average commercial cartridge is .002 smaller or shorter than minimum headspace, the RCBS Precision Mic allows you to measure cartridge headspace before and after shooting the cartridge to set up your reloading dies.
https://www.milsurps.com/images/imported/deleted.gif
Also Savage and Stevens makes rifles that you can easily adjust headspace on with a simple barrel nut wrench, you can get the Stevens 200 for under $200.00.
https://www.milsurps.com/images/imported/deleted.gif
If you want to make you actions flex MORE just put a little grease or oil in the chamber BUT this is hard on the action and increases bolt thrust which in turn unduly pounds the heck out of your action and increases headspace.
https://www.milsurps.com/images/imported/deleted.gif
https://www.milsurps.com/images/imported/deleted.gif
Jim KQuote:
Originally Posted by Jim K
Headspace is governed by the cartridge cases you shoot and not the rifle, the .303 British is a perfect example, commercial cases can be stretched beyond their design limits in the Enfield chamber and self destruct in just a few reloadings.
On the other hand a rifle with a tight chamber and tight headspace settings will strain the cartridge case far less.
If I remember correctly cartridge cases are made from five different grades or specifications of brass and American .303 cases are one or two grades below what would be used in the upper pressure category as in the .308 Winchester and above.
I was taught the finer aspects of reloading by a benchrest shooter and machinist and benchrest shooters like tight chambers for preserving their brass and accuracy.
By my standards a 30-30 has a loose chamber and longish headspace, I stopped counting how many times I have reloaded my 30-30 cases 20 years ago, on the other hand three reloadings from a Winchester case in the .303 is extremely short lived.
https://www.milsurps.com/images/impo.../carbine-1.jpg
It boils down to chamber diameter and headspace and chamber pressure for case longevity, with long life going to the tight chamber.
My bottom line here is the Enfield rifle gets blamed for our poorly made American .303 cases which the factory downloads to a lower pressure to avoid law suits, I believe these American made cases are made from brass in the 30-30 and 30-40 class or spec.
This book tells you to set your headspace .003 over your rim thickness, on my Remington and Winchester cases the rim thickness averages .058, this puts your headspace at .061.
https://www.milsurps.com/images/impo...curizing-1.jpg
https://www.milsurps.com/images/impo.../HSGauge-1.jpg
I don't know how I missed the .303 case gauge on the Wilson website.
I looked at the RCBS website, and saw their cartridge gauge, but saw they did not offer it in .303. I believe what you are telling me is that I can get .303 shoulder movement information from using the .308 RCBS Cartridge gauge. Is this true?
I am familiar with the differences in backthrust based on chamber conditions. I recently saw a series of pictures of .30-30 cartridge case heads with pressure indicating film on them: oiled cartridges showed the most pressure, followed by cartridges with the precise headspace of the chamber, the least pressure shown by chambers .010" over cartridge headspace. When studying action springyness, I'm going to have to pay particular attention to maintaining several standard chamber conditions: not just oil, but the same headspace.
I use the .308 precision Mic on my 7.62 Ishapore 2A1 and NOT on the .303 British, if you know how long your .308/7.62 case is you can get your headspace with feeler gauges or an unfired case and a spent primer and not need headspace gauges.
https://www.milsurps.com/images/imported/deleted.gif
On the Enfield you can insert feeler gauges between the right locking lug and the receiver to get your headspace (head gap clearance) with a unfired case in the chamber. You can also insert a fired primer in the same empty case to get your head gap clearance by starting the primer in the primer pocket and then chambering the case. Measuring the case length before and after inserting the primer gives you head gap clearance and this added to your rim thickness gives you your actual headspace measurement.
https://www.milsurps.com/images/imported/deleted.gif
EH posted
>>>If I remember correctly cartridge cases are made from five different grades or specifications of brass and American .303 cases are one or two grades below what would be used in the upper pressure category as in the .308 Winchester and above.<<<<
Do you have any citations to back this up?
Quote:
Originally Posted by ireload2
The last time I had a citation it cost me over $100.00 :rolleyes:
Are you checking my memory or do you think a 38 Special cartridge case designed for a max chamber pressure of 17,000 Cup is made from the same grade brass as a 300 Win Mag at 54,000 CUP.
As I said “if I remember correctly” cartridge cases are made from five different grades of brass BUT the requirements can vary for individual calibers and the pressure rating of the cartridge case.
The photos below are not from what I read some time ago because cases are manufactured by two different methods, drawing and extrusion and the requirements and annealing are different for these two methods. Also the specs for military grade cartridge brass is different from commercial grade brass and I may have read it in a military manual.
As you can see below the copper and Zink mixture varies with the different hardness and pressure ratings and the variations in actual mixtures is endless depending on requirements.
As an inspector at a military depot the contractors were required to submit samples of their cartridge brass for testing and acceptance.
https://www.milsurps.com/images/impo...hardness-1.jpg
https://www.milsurps.com/images/impo.../scan001-1.jpg
Your listing is of the different material conditions for 70/30cartridge brass.
Depending on how the cartridge is manufactured including annealing all the material conditions from full hard to annealed may be found in the same case. Some cases may even include the extra hard and dead soft condition.
If you would like to see the military specifications they can be found at the US government "Assist" web site. Pick the quick search option and enter key word for a title such as "cartridge"
As you learn to use the site you will figure out how to get to cartridge and then within that document you will find a specification for "brass, cartridge"
Ireload2
The commercial 30-06 cases in my Springfield 03-A3 with its larger diameter chamber and longer headspace lasted much longer than commercial .303 cases in my Enfields with there equally long and fat chamber.
This tells me the American made .303 British cases I’m using are not designed for the advertised pressures that are in our reloading manuals, on top of this you have thin rims and small base diameter of our American made cases.
You used different cases to solve your problem that fit the chamber better, and I want to find out what is wrong with the existing .303 cases and see if the manufactures will improve them.
Privi Partizan is making .303 cases with larger base diameters and thicker rims and when fired do not stretch in the base web area on the first firing in Enfield’s with headspace in excess of SAAMI standards.
I’m playing the part of the devil's advocate and not blaming the Enfield rifle for the problems I believe the cases are causing, I’m not looking for something to blame the problem on I want to fix the problem.
I have already seen the specs for military brass because I worked as an Inspector at a military depot, what I want to see is the American commercial specs for .303 cases and what chamber pressure the commercial factory .303 ammunition is loaded to.
In the photo below on top is South African PMP .303 loaded ammunition in a Wilson’s case gauge, it has a larger base diameter and thicker rims than American made cases, in the bottom photo is a new unfired Remington case and they don’t even know where to put the shoulder of the case.
If our American manufactures don’t know where to put the shoulder of the .303 case why should I trust them to make cases out of brass rated for 45,000 CUP.
https://www.milsurps.com/images/impo...twocases-1.jpg
My best suggestion is to get the British engineering drawings for the maximum and minimum cartridges and compare them to the maximum British chamber drawing. I think you will find a lot of clearance built in. (As long as manufacturers comply with the industry standards they are covering their butts liability wise.)
Then get the SAAMI drawings for the same and compare. you will probably find the same huge amount of clearance.
Once you have done this compare a similar cartridge and chamber that you know gives long case life. That includes almost any other cartridge except a .22 Hornet and a 6.5 Arisaka. I think you will find the Brits designed in more clearance than almost any cartridge developed after the black powder era ended.
This same issue occurs with the Japanese 6.5 Arisaka in both the Type 38 rifle and the Japanese Type I Italian Carcano rifle. The chamber is much larger than current available Norma brass. No blaming WW for this one. I have both Jap rifles and the cartridge to chamber fit is terrible. They even call the bulging cases the Norma bulge. On the other hand I have a 6.5 Italian Carcano. It has a normal chamber to case fit and the brass appears that it will last a long time.
I understand why you are putting out this effort. The .303 was the second cartridge that I ever loaded for in about 1969 or 1970. That first rifle was a worn out Lithgow 1916 #1 MKIII* with a new 1942 barrel. I had separations with it right from the start with Federal, Winchester, Remington and Norma brass. I did have some boxer primed military brass WRA 1943 that lasted a little better. I sold that rifle to my brother and bought a #4MkI. It did the same thing with the same dies and brass. I sold that rifle and now have another #4Mk1. This rifle has not been so bad but I started out with very light loads in it. Due to my past experience I never shot the rifle much since I am not in the habit of wasting money on new brass that will promptly separate.
About 15 years ago I found some 30-40 Krag brass by both Remington and Winchester that checked .455 at the rim. I made a few cases and they lasted much better than any .303 brass. At that point I thought I would try the .444 marlin brass not because it was cost effective but just to learn if they cut down the incidence of failure. They did though I have not shot them all that much either. They are a lot of work but I did the work to learn more about making brass last.
In our discussion about the case grabbing the chamber wall, there is one contradiction with the Lee-Enfield. If you try to insure the case sticks to the chamber the pressure of the load is high enough to stretch the case ruining it. And if you lube the case it puts more load on the action. The problem is neither is a nice option. The 500 new WW cases that you bought cost more than my rifle is worth. I would never use and destroy that many nice new cases just to lighten the load on the action. For me my rifle is more expendable than 500 new cases. That is why I tend to fire form with lubed cases and use reduced loads.
Another thing you might look at is the weight of the various cases.
Winchester brass is known to be light and relatively hard. In a close fit chamber that works well for lots of powder capacity and high pressure.
However the hard brass is less ductile and is easier to crack.
The HXP brass that I have weighs about 30 grains more than WW brass so it has heavier side walls. The .444 brass also weighs about the same as the HXP brass 190 grains. The 444 brass has much heavier side walls near the head than the brands of .303 brass that I have sectioned. I will restate though that I have use both Remington & WW .303 brass in 6.5 Dutch rifles with zero head separations. However the 6.5 Dutch chambers are a very close fit for the brass and the Mannlicher action is pretty strong and lock in the front.
I am surprised that the commercial brass companies sell brass as light and as thin as they do for .303s. They separate a lot creating a hazard. If it were me I would make the case walls much thicker to stop the separating or get out of the business. While thicker case would cost a little more I am sure consumers would pay a $.10 for better brass.I don't think there is anything wrong with their brass in a more normal applications but Lee-Enfields are not normal.
I have always found the Wilson tools very high quality but in the case of the .303 the actual head space is determined by the rim thickness. You could talk to the people at Wilson to find out if the shoulder in the gauge is supposed to mean anything. You might try giving Mike at CH Tool & Die
a call and asking him about the drawings even if you have to bribe him buy buying a set of dies. He sent me Zerox copies of some original British ammo drawing for the 7.65 Argentine Mauser. Even with engineering drawing you have to be careful because some sources differ.
While you are comparing new cases to you Wilson gauge have you tried fired cases in it? The once fired HXP brass that I bought has some of the goofiest shoulders that i have ever seen. I think there may be a lot of difference between loaded ammo and Lee-Enfield chambers.
In the end you may find that .303 British brass can be a lot better but I don't know how you get a company to change their product. They have been that way longer than I have been loading. My approach was to try something on my own and not worry about changing the big companies.
When do you get to go back to the other forum?
Ireload
You are not telling me anything I do not already know because I have been reloading for over 40 years and we have gone over all this before. The best method I have found for fire forming .303 cases is using the rubber o-ring method and you will have zero case stretching because you have zero head gap clearance.
In the posting at Gunboards that was deleted I went into detail on this method, in Parashooters Headspace 101 he used nylon monofilament instead of the rubber o-ring to hold the case against the bolt face and reloaded the cases 19 times without any case stretching.
The secret is in the fire forming and not letting the case stretching in the web area get started in the first place.
I also said before the American manufactures are loading factory ammunition to below 43,000 CUP and are using a lower pressure rated cartridge brass which makes them fall apart above that pressure.
You may have a lot of reloading experience but so do I. Plus my entire working career had been involved in machining, metal working and engineering.
You assert good things about your method but have you actually shot any brass to destruction?
What size O ring are you using so I can duplicate your tests?
I would like to try the O rings with .444 brass and .405 brass.
One of the reasons that you may have found no thinning in the HXP brass you have I believe you said it had been fired in a machine gun. That might make a big difference if the machine guns is much heavier and stronger than a Lee-Enfield action.
Is the machine gun fired HXP still available anywhere.
Have you checked your fired brass in the Wilson gauge?
It seems you conveniently ignore my questions.
You are forgetting something very important here, I did not ask you for any advice nor do I want any of your advice, the main reason you came here is to extend the argument, fight, disagreement we had at Gunboards to this forum.
This thread last saw activity before you asked your question on April 6, 2009 and that was over a month ago, the only reason you are here is to stir up more trouble like you did at Gunboards. Take your grudge, ego and B.S. and go someplace else.
Have a nice day :D
Seems to me there's no significant difference in the shoulder location of unfired .303 cases or loaded ammo in my little stash - regardless of national origin
https://www.milsurps.com/images/impo...mplesgif-1.jpg
Anyway, it hardly makes much difference since the chambers are designed with plenty of clearance at the shoulder, and the intent is for the cartridge to stop on the rim long before the shoulder touches (mud, not reloading, being the original plan).
Near as I can figure, the purpose of the shoulder in the Wilson gauge is to alert the user when the head-shoulder dimension is too long - which would leave the cartridge base protruding above the back end of the gauge. That could be a useful bit of information to help reject cases that need some F.L. sizing to fit in a (mythical?) "standard" chamber.
Mr. Horton is confused about my case stretching tests. The one I reloaded "19 times without any case stretching." didn't involve any spacers (neoprene, nylon, or otherwise). It was an R-P commercial case from which I removed the rim to demonstrate that the skinny .303 shoulder was entirely adequate for rimless-style headspace control in a neck-size-only operation. As can be seen in the image below, there ain't no place to put a spacer on this one!
https://www.milsurps.com/images/impo...rimless3-1.jpg
I suspect Ed was the unlucky purchaser of a bad batch of Winchester cases - which may have been "outsourced" (Can you say "S&B"?) instead of made in USA - and he's made some questionable generalizations about American brass quality on the basis of this experience. As long as some of us keep reminding the audience that "it ain't necessarily so", there's plenty of room for lively discussion. (Sometimes he's even been known to admit someone else might be right.;))
In this case Mr. Parashooter I’m NOT willing to admit you are right.
I have NOT made some questionable generalizations about American brass.
IF the American ammunition companies are in fact downloading .303 ammo to pressures lower than 43,000 CUP it would explain why the .303 cases do not hold up.
I also do not want YOU taking the liberty of making assumptions on the cases I buy or the tests I conduct on them, your comments here are uncalled for and insulting.
They are especially insulting because you think you are the only one capable of reaching the correct conclusion in these forums or anywhere else, in essence you are saying Parashooter is never wrong in your typical patronizing manor.
ireload2 has the exact same problem you do, he oils all of his cases before he shoots them and ignores the word “bolt thrust”.
Have a nice day
The shoulders on my Remington and Winchester cases are not assumptions on my part Mr. Parashooter especially when the cases have five different lot numbers and are newer than your cases.
I truly wish you would think the next time before YOU make assumptions.
https://www.milsurps.com/images/impo...houldera-1.jpg
https://www.milsurps.com/images/impo...twocases-1.jpg
I am not arguing with Parashooter or Edward, but I feel that something is confused.
I do not fire gauges, I fire real-world cartriges. And the examples I have from PMC and S & B look EXACTLY like the pics provided by Edward - a good 1/16" stretch after firing. Why?
The 303 is a rimmed cartridge. Which means is it supposed to be held by the rim. The clearance (I am trying to avoid the word headspace) between the rim and the bolt face when the cartridge is pushed forwards by the strike is the amount by which the case can stretch. IF and ONLY if the case shoulder perfectly matches the chamber before firing. Otherwise the shoulder will also move forwards. Which it does. As is inevitable in chambers cut to cope with dirty/max tolerance cartridges that were NOT intended to be reloaded.
The PMCs in my collection have a rim thickness of 0.056-0.057", the S&Bs about 0.058-0.059". I do not know what the maximum bolt face to chamber spacing may be in practice, but it is probably more like 0.070" for real-world Enfields.
Whatever the value, this clearance of 10 to 15 thou is MUCH less than the stretch observed by Edward, myself, and my friends who shoot Enfields. We should think of the case being pushed forward rather than the base being pushed back.
The root of this trouble is that (surprise, surprise) the British were so bloody-minded that they did not make rifles to SAAMI specifications. How could they have been so short-sighted as not to realize around 1900 that the Americans would set up an organization in 1926 that would define tighter measurements? All those Tommies in the trenches should have been saying "Sorry sarge, I can't use this rifle, I can chamber any old cartridge, so the chamber is obviously too generous" - or not?
Seriously, the answer it to adjust the cartridge cases to fit the rifle, not the rifle to fit gauges that were defined decades after the rifle was built. That means, as for so many milsurps, fire-forming and neck-sizing, dumping cartridges that show too much stress before they separate. In effect, this means treating all cartridges as if they headspaced on the shoulder, and thus only re-using the cases in the rifle in which they were first fired.
Patrick
I visit many gun related forums due to my interest in shooting and collecting and am fully aware of the altercations and personality clashes that occur.
This Lee Enfield Forum has been largely free of such unpleasantness.
We the moderators intend to keep this and all other forums on this site a place where we encourage the open exchange of information amongst the general military surplus collector community, thereby helping all of our members to better enjoy their chosen hobby.
I don't feel that anyone on this thread has "stepped over the line" but am very aware of the possibilities for this to spiral downwards. Hence my appeal to all the contributors to avoid any personal jibes or attacks - discuss your theories and present your information - I for one am interested in the content of this thread and would like to see it continue. Remember at the end of the day it's OK that not everyone agrees with you :slap:
Amatikulu
I reckon for military purposes the only real critical controlling dimension is the rim thickness of the case. Commercial ammo makers also don't worry about reloading, they just want you to buy more ammo. If case life stinks all the better.
Something I've noticed is that No 1's and No 4's chambers are cut differently. If sorted and neck sized only cases fired in a particular "model" will fit quite a few rifles w/ no further attention as to EXACTLY which weapon in which they were fired. Works espcially well with the "T's"!!! Oh, No 3's don't fit well in the others, but there's only one that I've shot extensively.
Amatikulu
The problem Amatikulu is oil and grease in the chamber and increased bolt thrust is NOT a theory nor is the damage it does a theory, they are facts.
The problem is people are unwilling to admit lubing cases to fire form them can cause damage and the books say to remove all oil and grease from the chamber.
The problem Amatikulu is this post WAS reopened to start an argument.
The problem Amatikulu is people would rather argue than admit they are wrong.
The following are not theories they are printed warnings, one was written in 1946 specifically on the Enfield rifle and the other is from a current reloading manual.
https://www.milsurps.com/images/impo...ssstrain-1.jpg
https://www.milsurps.com/images/impo...can0048a-1.jpg
I have seen this idea with fair frequency and eventually decided to test it -Quote:
Originally Posted by Patrick Chadwick
https://www.milsurps.com/images/impo...xialdemo-1.jpg
I believe that when a rimmed cartridge is fired with generous shoulder clearance the case expands outward to fill the chamber and there is little or no elongation (stretch) due to brass being "pushed forward". I'd be delighted to hear details of any tests that either confirm or refute what I've concluded from my little experiment.
-------------------------------------------------------------------------
Ed, I apologize for the offense. It was not my intent. I have great confidence in your measurements and observations about the .303 cases you've examined and shown us. That they differ from what I've experienced tells me there has been some significant variation in production - enough that I question the value of any generalization based on what either of us have observed in a variety of specimens.
To be specific, I question assertions that -All of these may be valid points. I'm just saying that I haven't yet seen any conclusive evidence to support them and my experience differs. Please don't stay angry.:surrender:
- US makers are routinely loading .303's to reduced pressure.
- Shoulder clearance is a defect in (new) rimmed cases.
- There is a qualitative difference in the metal US makers employ for .303 cases.
Practical news as a change from hotly argued theory!
I have just done a quick check according to the Parashooter method, using a 9 para case fresh out of a long-barrelled Artillery Luger (not mine, alas!)
PMC shoulder before firing 2.596"
PMC shoulder after firing 2.630"
PMC cartridge length before firing 2.212"
PMC cartridge length before firing 2.231"
Increase in case length 0.019"
Shoulder movement 0.034"
That 0.034" shift of the shoulder is a lot more than any bolt face - cartridge base clearance. That clearance could be zero, and the stretch caused by the shoulder movement would still be alarming.
Chuck away those gauges and fireform some cartridge cases to fit the real rifles!
Patrick
Parashooter, your latest posting appeared when I had already posted measurement. That was a very neat idea with the scribed lines. Have you got any explanation as to why the first scribed line (at 1.570") actually moved back towards the base? It is surprising that the spacing of the three lines has remained the same. although the shoulder has moved from between the first and second lines to between the second and third lines.
If the shoulder is just rolling forwards, without any stretching, surely one would expect the gap to expand between the first and second lines, and to contract between the second and third lines?
Patrick
Parashooter
I’m not really angry at you, but your timing arriving in this posting did not help matters, I’m on suspension at Gunboards for arguing this same subject matter and ireload2 decided to bring the argument here.
One of the problems in these forums is the moderators are not rabid bullethead reloaders and can’t tell the BS from the facts so they say “both posters statements have merit” trying to be politically correct. My problems is I spent the last 25 years at a military depot trying to get people to read the manuals as an Inspector.
I brought every Enfield manual I could find into the Enfield forums hoping to bring the forums “into the light” and we are still in the dark ages.
NOTE: All cases get shorter when you first fire them and thereafter start getting longer until they need trimmed due to brass flow.
I will post more later with some photos of older Remington .303 cases and newer .303 cases, methinks the bean counters got involved…………………..
And NO I’m not mad at you because YOU are a bullet head reloader who is NOT rabid. ;)
When I responded to this board anyone was free to respond. That you chose to was your choice only. Instead of engaging in discussion all you can focus on is the 2 narrow straws that you have been grasping at all along.
1. All American made brass is junk......with no real back up
2. You can fix the problem by fire forming with an O ring - no test results offered.
When asked for results you have never responded, you never answered the questions.
I asked what O ring you use ... No answer
I asked if you have tested a case to destruction ....No answer
It is apparent that any discussion with you will always reach the same dead end. A lot of conspiracy theories and no test results.
So be it. End of discussion with EH. EH - If you are unable to respond in a positive manner to my posts in the future please do not respond at all.
It seems that EH tries to poison the water for me where ever he goes. Please leave your finger pointing references to me out of your posts. What ever happened to you at gunboards was in the making long before I showed up there.Quote:
Originally Posted by Edward Horton
I came here to continue the discussion with whom ever wanted to discuss it since there was an interesting similar thread here.
A friend had a head separation with his No 4. He gave me the remains as a fine example and two other cases obviously on the verge of separation, having wisely decided to bin the whole batch (from S&B). Not having anticipated this effect, he had not checked the case length before firing.
Example 1. Case length 2.239"
Example 2. Case length 2.239"
Example 1. Shoulder position a/c the "9 para" method 2.670"
Example 2. Shoulder position a/c the "9 para" method 2.672"
In other words, the shoulder has moved forwards a whopping 0.074-76" compared with the "new" value of approx. 2.596 given in the previous posting.
The case lengths are beyond the minimum chamber length a/c the CIP data sheet (I do not have the SAAMI info).
Sorry to bang on about this guys, but evaluating Enfields with SAAMI or CIP gauges is obviously an academic exercise which is not going to solve practical shooting problems. I do believe Peter Laidler has said something about this in the past. Peter, if you are following this thread, perhaps you would care to comment?
Patrick
Para,Quote:
Originally Posted by Parashooter
I have a similar observation. I have formed .303 brass from once fired .30-40 Krag brass. There is not really much to it other than trimming to length and resizing to retain a bullet. The Krag shoulder is far below the .303 shoulder.
It seems many hand loaders can only think of brass as stretching longitudinally.
What I have observed is that brass tends to stretch radially first then longitudinally. In the case of the Krag brass it had a different surface color at the shoulder than it did over the neck. When fired in the .303 chamber the case merely expand radially. A new shoulder is formed at the proper location in the .303 chamber. The color tone and previous sizing marks on the Krag shoulder remain where they were, they are just expanded in diameter.
Once fired Krag case on the left. Note color of shoulder.
The case on the right was trimed to .303 length and fired in .303 #4MK1.
Note color band on the should is still in the same location.
This from my Frankenstein box of .303 brass that includes reformed .444 Marlin, .30-40 Krag, WW Super, Western Super Speed, two different R-P headstamps and Herter's.
https://www.milsurps.com/images/impo...brassJPG-1.jpg
EDG
For me, that is the No. 1 question. To understand how/why the head separation occurs, with the aim of doing something to avoid or at least reduce it.
Patrick
Two main factors, I think. Diameter of the case versus the chamber where the web thins out (probably of secondary importance) and case wall thickness. Granted there is some rearward displacment, but in the generously proportioned chamber a thin case will stretch and thin out near the juncture of the solid base. When sized, the displaced metal will not "rethicken" but will just displace forward. The distress is compounded w/ each firing and sizing cycle. Multiple factors at work here. Dang, even benchresters experience brass flow and other evilness(just takes longer).
The first line moved back because the body of the case expanded. Since brass was "neither created nor destroyed" the increase in diameter resulted in a decrease in length. Here's an attempt to show this principle using a rubber band I took off a dead lobster -Quote:
Originally Posted by Patrick Chadwick
https://www.milsurps.com/images/impo.../elastic-1.jpg
Elastic cylinder (rubber band) loses length as diameter is stretched.
I think it's mistaken to assume that the case expands from rear to front, "rolling forward" as you say. Here are a couple of examples showing that the forward part of the case, being thinner-walled than the rear, actually expands first.
https://www.milsurps.com/images/impo...k31blank-1.jpg
7.5 Swiss blanks made from .30/06 are very much undersized. Low pressure of blank charge blows out shoulder and front 1/3 of case.
https://www.milsurps.com/images/impo...03bulged-1.jpg
The .034" shoulder movement you describe sounds normal to me, just the usual "fireforming" action. One plausible way to explain the .019" total elongation is as an accumulation of clearances. For example, an .056" rim, .071" headspace (.015" end-play), plus .003" action flex, add up to .019". If you were to try the same test with the case or chamber lightly lubed, you might see less change in total length.
https://www.milsurps.com/images/impo...dsepcast-1.jpg
Upper case was neck-sized, loaded, and fired 10 times with 180-grain bullet, 41 grains RL15 (2450 fps). It elongated .002"-.003" at each firing, separated on the 10th shot, and was stuck so firmly that a normal "broken-shell extractor" wouldn't move it. (Pounding on chamber cast finally got it out.)
Lower case has been fired 15 times with same load but was lightly lubed with castor oil before each shot. There has been no elongation (and no wear on my SMLE that I can see or measure). When I get some more time, I'll increase the load to 42 grains (Alliant's maximum), see it I can get it to 30 or 50 shots and check again for any damage to the rifle. (Not recommending anyone else fire lubed cases in their Lee-Enfields - just trying to find out how it works in mine.)
Here's the best illustrated explanation on the mechanics of head-separation I've found -
https://www.milsurps.com/images/impo...amoregif-1.jpg
Notice that Naramore says the stretching occurs at the rear of the case (S) while the front is "locked in place".
This is my attempt at the same illustration, updated with color and motion -
https://www.milsurps.com/images/impo...estretch-1.gif
Wish I'd called the initial space between case and bolt "end-play" instead of "Head clearance" but I'm too lazy to re-do the animation now.
Thanks you for some very enlightening photos! And the animation convinces me that the answer is to make the head clearance as near to zero as you can. In other words - neck sizing only. Am I right, or am I missing something?
Patrick
Para,
Not only is the brass thinner at the shoulder but it is also softer from annealing and therefore has a lower tensile strength than the work hardened brass near the head.
I have had the same results with hydraulic decapping of brass 7.62X39 berdan ammo. Using a water filled case I drove a 5/16 punch into the case and bulged the shoulder and front 25% of the case similar to your photos. Alas there were no digital cameras in those days.
The shoulder on a .303 is just there to confuse you.
I like the expression "end play". Makes immediate sense as a mechanical engineering term, and avoids this irritating/confusing head business.
So we want zero end play. Or as near as we can get?
Patrick
That, as little sizing as possible and good brass!
Having used the "9 para" method to measure the case shoulder movement, I have now applied the "pushed in primer" method to estimate the end play on 3 examples of the extended Enfield family. Measurements were made by holding the case in the lathe chuck and using the cross-slide to move a 1/100mm-reading dial gauge with rounded tip across the cartridge face.
End play:
No 4 Mk 2.....0.26 mm = 0.010"
No.1 Mk V.....0.20 mm = 0.008"
both with new cases
M1917..........0.06 mm = 0.0024" i.e. between 0.002" and 0.003" with a fired and neck-sized case. Bearing in mind that the bolt will compressed slightly on firing, and the brass has a slight spring-back, this is probably and low as one can get.
I know this is a slight case of comparing apples with pears, but I do not know in which rifle the fired 303 cases were used. I will remedy that next time.
The M1917 is "fed" only with the excellent cases from Geco. I have no idea how many times they have been fired. If they ever get too long they will be marked by a file notch when they are trimmed, and binned after two or three trimmings. On the basis of their performance to date, I think I already have a lifetime's supply.
Cases fired in both Enfields show the suspicious broad bright ring that indicates stressing of the body-base junction. As the animation provided by Parashooter shows, the body can expand quite freely in a radial direction, EXCEPT where it joins the base. This is usually where the cases come apart, and I suspect it is the radial stress at this junction that does the damage by causing a radial necking, not the longitudinal expansion. On the 303 cases there is a visible step at this junction after firing. Which would suggest that it is generous chamber diameter, not length, that causes the trouble. Further throughts on this would be welcome.
Patrick
What I have been trying to get through to people in this age of the globalization of our economy with corporate profits, corporate bonuses and good old fashion greed things are changing.
Below is 20 some year old Remington ammunition with a loaded factory round in a Wilson case gauge.
https://www.milsurps.com/images/impo...IMGP5197-1.jpg
https://www.milsurps.com/images/impo...IMGP5198-1.jpg
Below is a currently made Remington case purchased from Midway and I have Winchester cases that drop this low in the gauge also. The “new” brass is made differently and is of a lower quality/different grade brass than the 20 year old ammunition is. I’m saying this because the “new” cases from Remington and Winchester are stretching and thinning faster or sooner than the “Old” brass and that was bad enough.
https://www.milsurps.com/images/impo...IMGP5199-1.jpg
https://www.milsurps.com/images/impo...IMGP5191-1.jpg
This why I was asking about British chamber pressures, reloading manual pressures and stating something is wrong with our American made cases, because they are not lasting as long as they once did.
The problem at Gunboards was you can’t get your point across when people want to argue and change the subject from .303 cases to .444 and .405 cases and get the threads locked or deleted.
Hi Patrick,Quote:
Originally Posted by Patrick Chadwick
To test the same observation I have made cases from .30-40 Krag (.455 at the head) and .444 Marlin (.458 at the head after forming). The .444 Marlin brass is heavier than most .303 brass and the .444 Marlin is a more modern design with higher pressures than most rimmed cartridges designed for lever action rifles. These reformed cases look pretty ordinary after firing. There is no step or bulge at the pressure ring. My next task is to shoot some of these to destruction since they have not shown any ill affects with just a few reloads.
My hope for these tests is to prove that the huge diametral/radial clearance in the LE chambers contributes significantly to the reduced case life in the LE.
The tests involve the .30-40 Krag R-P case which is as thin as the .303 R-P case and weighs 162 grains. The 444 Marlin cases to be tested are much thicker at the pressure ring and the case weighs 190 grains.
It is my theory that the LE rifles suffer increased rate of case head separations due to:
1. Ammo to chamber fit has a lot of diametral clearance, (meaning .008 to.010 diametral clearance)
2. Generous headspace
3. Long head to chamber dimensions
4. Relatively springy actions.
One through three can be dealt with by various loading techniques.
Perhaps if they are all dealt with they will minimize the affects of #4.
If not, there may be a way to deal with #4 but it is sort of a last resort.
EDG
With full-power loads in rear-locking actions, even neck-sizing and good brass won't completely eliminate the small (.002"-003") amount of stretch that occurs because there is some 4" of elastic steel between bolt face and locking lugs/shoulders. The thinner the cross-section of bolt and receiver, the more stretch occurs. (That's why an SMLE flexes a bit more than a No.4 and a Remington 788 flexes less than any Lee action.) As JM noted earlier, the stretched section isn't corrected by sizing, it just keeps adding up. When accumulated stretch gets to about .020", our thinner cases are toast. Heavier ones can stretch more before they fail, but they'll give out eventually.
I don't have a P14 to demonstrate how front-locking helps reduce stretch in .303's, but once did a rough test comparing front-locking (K31) and rear-locking (K11) Swiss rifles for this effect. Even with substantially higher estimated peak pressure in the K31 load, cases lasted considerably longer in the front-locker.
https://www.milsurps.com/images/impo...6/75seps-1.jpg
These cases were not new at the beginning of the test, but had comparable histories. Norma 7.5 brass is surprisingly soft and light compared to some others -
https://www.milsurps.com/images/impo...headsect-1.jpg
This .284 case has been fired a lot in rear-locking actions, but is so thick-walled it still has a long life ahead.
As far as I know, there are two ways to extend case life in Lee-Enfields, beyond the normal methods of neck/minimal sizing and using improvised rim spacers on initial firing of new brass:Patrick, I can't agree with ". . .it is generous chamber diameter, not length, that causes the trouble. . . " Head separations occur when we have end-play and/or action flex, even with cases that are a tight fit in the chamber (like the 7.5's above). Also, sectioned cases show that the thinning occurs well above the point where walls expand to fill chamber, as can be seen on the well-worn Winchester and Federal cases in this picture -
- Use reduced-pressure loads to minimize action flex.
- Lube cases - with the caveat that many respected sources consider this hazardous to rifle and shooter.
https://www.milsurps.com/images/impo...headsec3-1.jpg
Ed, I think you're on to something with the old/new comparison but I'm not convinced it's the quality of the raw material that has changed. Is is possible the new cases are just thinner and lighter? Have you compared weights and wall thickness between the two "generations" of R-P cases?
Parashooter
I checked some different cases for weight
S&B 182 grain avg
Privi 172 grain avg
Win 169 grain avg
Rem 162 grain avg
There was only at most 1 grain difference between the old and new Remington cases????
The Winchesters weigh more than the Remingtons but longevity is the worst
The Privi bases are .010 thicker than the Rem or Win and the base diameter is larger.
Fire forming with the rubber o-ring method produced cases without any thinning or stretching in the web area, and the o-ring centers the base of the case in the chamber.
https://www.milsurps.com/images/impo...IMGP5098-1.jpg
Now we are getting somewhere. Comparison new cases verses new old cases. The composition of the brass has been changed. Eds thoughts on this have paralleled my experiences. I agree with most of what has been said but it comes down to one common denominator the case.
>>>The composition of the brass has been changed<<<
This is not proven.
My experience of 35 years ago gave results just as poor as is common today with the same brands of brass.
Thanks for the weight and wall-thickness survey, Ed. So much for my raw mass theory!
As the specs you posted show, cartridge brass is a pretty simple alloy, around 70/30 copper/zinc with low levels of allowable impurities. It's a standardized product the ammo makers buy in huge rolls from the brass mills. If there's a difference in the quality of finished cases lately, I suspect much of it arises during their manufacture - whether from changing the number or rate of draw operations to speed production or maybe skipping some annealing (saving energy?) is certainly beyond my limited knowledge. No evidence, I'm just trying to apply a little logic to the question.
Fortunately (thanks to reduced loads and castor oil :nono:), I'm still using a few of the WRA-43 cases I first reloaded in 1958 and have many others that are "only" 20 or 30 years old. It's unlikely I'll ever need to buy more since "lifetime supply" is becoming a smaller quantity with each added candle on the birthday cake.
I have cases that are a different quality of brass from the 60s and 70s. they have been used in much higher pressure loadings than the parent 303 cases and are still sound.[303/22, 303/243, 303/25,303/270] That tells me it is not the chamber though case or shoulder splits did occur using current cases but no head separation. Using current cases in 303 head separation does occur sooner the brass looks different there may also be a difference in manufacture of the cases ie annealimg this is the unknown.
But you have not covered the full conditions of use.Quote:
Originally Posted by Bindi2
There is a high probability that your .303/XXX custom chambers were/are not as sloppy as the original Lee-Enfield chamber. You also did not mention what action was used on all the other variants. If an action other than a LE was used the data is not related to theis discussion. In addition without pressure test data your pressure estimate are speculation.
The conversions were built on English and Australian No1 Mk3 and Mk3*, P14 actions. The 303s any thing that chambered 303 pre 1900 on. Head separation is a more recent happening. You are correct that i can not give a precise pressure figure. Speed in FPS were known as was hard bolt lift. Case capacity was measured and taken into account. Different case manufacturers were used and sorted to their best use in all of the above.
At this point it looks like chemical analysis tests and crystalline photo analysis in the longitudinal and transverse sections of various new and old unfired cases would have to be made to prove anything. Anybody w/ resources?
A few years back I pointed out that if one is using brass with thin rims as in the US produced 303 brass one can take a thin o-ring and force it over the cartridge to the rear of the case at the front of the rim.
This does a few things ----
a) it take up all the slack and forces the cartridge back against the bolt face thereby reducing any bolt thrust to --just thrust--not a moving hammer to the bolt lug faces.
b) it also benifits us by centering the cartridge in the chamber and thus hopefully centering it in the bore increasing acuracy by starting the bullet through the neck and the start of the rifling.
If you use the o-ring method you will immediately notice two things --but do this in a No1 mK3------
A)
1)Fire a round with no o-ring--now take the cartridge and look at the primer and the firing pin indent--off center isn't it. (if you have normal oversized chambers like 99% have)
2) look at the cartridge at the front of the rim the cartridge will be bulged unequally as is normal in oversized chambers.
now---
b)
1) take a cartridge--install an o-ring over the cartridge --here you have to decide the size it is up to you--they stretch well so use trial and error in dry fitting-- now take that cartridge or a few, maybe with a two or so different o-ring sizes installed. Fire them and look at the firing pin indent it should be in the center or noticeably more centered.
2) the brass will show equal expansion equally around the cartridge--this is good for the brass as well as the hoped for accuracy.
Check it out on older Lee's it works and works well.
I posted this on the older CSP forums for the guys and gals firing the 303's. I hope it helps you all with the brass expansion--your bolt thrust(hammering) accuracy etc.
https://www.milsurps.com/images/impo...g?t=1244297759
Have a great day.
Regards
Terry in Victoria
Terry in Victoria
Thank you very much, I could not remember who originally posted it at the old Jouster forum, I tried it out and it works fantastic, NO case stretching in the web area and the cases ARE centered. :thup:
Can I take it this idea did not come from the Red Green show as duct tape was not used. :D
(seriously thank you Terry it is a very good idea, and it works)
As a side note I removed the extractor to prevent the rubber o-ring from being cut and failing, do you remove the extractor?
50 fire formed Remington cases using the o-ring method, with centered primer strikes.
https://www.milsurps.com/images/impo...IMGP5096-1.jpg
Thanks to all who have contributed to make this probably the most interesting thread I have seen in months.
At the moment, my state of knowledge may be summarized as:
"Longitudinal and radial elongation play a role in creating the stress line that is a prominent feature in the typical Enfield head separations."
"This effect may be exacerbated by using brass of an inappropriate quality and/or thickness for the task."
"Head separation also occurs when the case fits the chamber better, it just takes more firings."
BUT
"The stretch that leads to head separation can be considerably reduced (eliminated?) by a lightly lubricated case. Really light. But not squeaky clean."
Now on the "Reloaders Bench" forum there is a thread "Case head exits rifle" where Parashooter provided the following quite from Hatcher:
"If the bullet had been dipped in grease, this generally meant that the neck of the cartridge was greasy too. The space between the neck of the case and the neck of the chamber was filled with an incompressible substance, and the first moderate rise in pressure found it impossible to expand the neck and release the bullet. Thus the powder was strongly confined right at the beginning of its ignition, and accordingly the pressure rose disastrously."
Hardly daring to argue with such an authority, I have noted that there is a certain degree of doubt as to whether or not Hatcher was following the army "party line" in this respect. Certainly thousands of BPCR shooters would be puzzled to hear that greasing bullets damages your rifle, as our everyday experience is that greasing in some form is absolutely necessary. And we are firing loads for 1000 yard shooting that go up into the 3000 Joule range, so we are not talking cats-sneeze loads here.
OK, you say, but blackpowder is irrelevant. I disagree, but let's look at a nitro-fuelled example.
I recently acquired a Swiss G96/11 rifle that is the best "out of the rack" milsurp for accuracy that I have ever had. I bought a pack of the Swiss GP11 surplus ammo which is perfectly tuned to this rifle (no surprise) and was surprised to see that the cartridges not only have sealed primers, but a wax coating aroung the bullet/neck junction to seal the joint there as well.
Of course, following the conventional wisdom of Hatcher, I cleaned the stuff off before firing. I wondered if the Swiss did that too, as cleaning up a 470 round package is, quite frankly, a bore. So I asked an eminent Swiss shooter, and I have no reason to think he was pulling my leg.
" Of course you don't clean it off," he said, "because on ignition the wax is simply squeezed out between the neck and the chamber into the throat and goes down the barrel with the bullet, incidentally preventing gas cutting and conserving the barrel."
Any comment? Was Hatcher right and hundreds of thousands of Swiss have been doing it wrong for a century? Is the typical bore on a Swiss milsurp ruined by the wax? Those I have seen are, without exception, beautiful, in a world where dealers are not afraid of selling rifles with ruined bores as if they were rare antiques. Are the bolt lugs hammered to death? Not that I have heard.
You see lads, at the moment I am tending to the hypothesis that if we are stuck with some degree of stretching which will lead sooner or later to head separation, but this can be practically eliminated, or at least greatly reduced, by a touch of case lubrication, then this perfectly fits my idea of creative laziness in quite simply not carefully cleaning off all traces of case lube from my rounds, but just wiping them down with a paper towel when they have been formed.
Saves work and improves case life - sound to good to be true. Is it?
Patrick
On the opposite side of the coin on oil and grease in the chamber, one was written in 1946 by Jim Sweet and the other is from a reloading manual.
The rubber o-ring method does not cause additional bolt thrust.
https://www.milsurps.com/images/impo...ssstrain-1.jpg
https://www.milsurps.com/images/impo...can0048a-1.jpg
It does not have to be one way or the other.
You don't have to chose between Mary Ann or Ginger.
In this case you can have both Mary Ann and Ginger.
The old wives tale about removing all traces of lube is of course never followed by the large majority of shooters. Most go to the range and start blasting with out wiping the oil that has drained in to their chamber after setting the rifle in the closet.
The Taisho 11th year is a light machine gun introduced in 1922, it remained in service until the end of World war 2. It has an unusual feed system consisting of a hopper mounted on the left side of the weapon. Five round charger strips are placed into the hopper and the gun strips out the rounds as they are fired, these chargers are the same as those issued to 6.5mm rifles, this was to allow any rifleman to supply ammunition to the machine gunner. This feed system turned out to be complicated and prone to stopages, in addition an integral oiler was included as the weapon required oiled cartridges for proper operation.
The Type 96 was introduced in 1936 to replace the Taisho 11. It is very similar but the hopper is replaced by a top mounted box magazine. The oiler was removed and the cartridges were oiled before loaded into the magazine.
The Schwarzlose Machine Gun M1907 was an extremely simple mechanism compared to other famous designs like Maxims. It was easy to make and proved reliable. The designer had managed to solve the problem with a delayed blowback system. The problem is that the breech starts moving backwards immediately as the cartridge is fired. The gas pressure is still very high and the walls of the cartridge case are expanded towards the chamber, which will cause very high friction. At the same time the extractor starts pulling out the empty cartridge case. The problem was solved by using very strong recoil springs and recoil parts together with a very short barrel. When the bullet left the barrel the pressure dropped while the kinetic energy of the recoil parts continued to pull out the empty cartridge case and reload the gun. The Schwarzlose machine gun has a device for oiling each cartridge to ease the reloading cycle. On each stroke oil was squirted into the firing chamber to lubricate the incoming cartridge case.
1912 some changes were made to the feed system and this change was called M1907/12. It had a straight top receiver and a simplified oil pad system instead of the pump mechanism.
As you can see some countries designed oilers into their machine guns to improve performance.
Polishing the chamber also improves case life as is mentioned on VarmintAls
In addition polishing your brass probably has much the same effect as oiling the cases. It reduces the effective coefficient of friction between the chamber and the cartridge case. It is also almost certain that an reasonable gun designer built in enough safety factor to a design to insure that oily ammo would not damage the action. An it is a fact that said designers know much more about the strength of an action that did some competitive shooter. Personally I am not going to let an obscure quote mined out of the back side of the internet over ride my personal judgment based on many years of successful reloading. In addition the .303 Lee-Enfield were given a larger chamber than originally designed just to accommodate dirt, mud and other battel field contamination. Certainly it was expected that both oil and water would be expected to get in some of these rifles in combat.
Looks like you missed the text surrounding that quote from Hatcher -Quote:
Originally Posted by Patrick Chadwick
The point of this post was to clarify that the pressure problems associated with greased bullets are the result of excess grease preventing the neck from expanding to release the bullet cleanly. This is very different from the added bolt thrust we get when lubricant on the case body reduces friction between case and chamber. NOT THE SAME THING! OK?Quote:
Originally Posted by Parashooter
When contemplating the waxy lubricant band that used to be featured on Swiss 7.5 ammunition (GP11), don't overlook the fact that the Swiss chamber features an elongated neck designed to accommodate it.
https://www.milsurps.com/images/impo...imlength-1.jpg https://www.milsurps.com/images/impo...gp117884-1.jpg
Swiss 7.5 chamber neck is significantly longer than cartridge case, leaving room for lubricant formerly applied during manufacture.
There are practical and "approved" uses for lubed cases. Before the development of the fluted chamber (which allows powder gas to prevent adhesion of case to chamber), it was fairly common for automatic arms to employ lubricated cases or chambers. Most of these were MG's or LMG's, but two well-known shoulder rifles, the US Pedersen .276 and the Swedish AG42 Ljungman are documented as requiring lubricated cases for reliable functioning.
None of this means that lubing your .303 cases and firing them in your Lee-Enfield is a recommended practice. I've been doing it for years with no problems - but I'm a reasonably conservative handloader and my Lee-Enfields are all in sound condition. Some very good people think it's a terrible idea and will damage something sooner or later.:nono:
I believe those who assert that radial expansion contributes to the kind of head separation commonly encountered by .303 reloaders are mistaken. Radial expansion puts the circumference of the solid case web in shear, not stretch - and it does so in a completely different location. Failure in this manner is very uncommon with good modern brass and I've never seen an actual example, but here's a lousy picture from an old book that shows what occurs and where -Quote:
"Longitudinal and radial elongation play a role in creating the stress line that is a prominent feature in the typical Enfield head separations."
https://www.milsurps.com/images/impo...naramore-1.gif
So ireload2 your main propose here in this forum is to carry on the same argument we had at Gunboards.
If the ammunition manufactures wanted grease or oil on their ammunition it would come that way from the factory, the ammunition comes grease and oil free and all written material tells you to remove any grease or oil from the chamber.
Ignoring printed warnings to justify your own shade tree methods of oiling or greasing cartridge cases does not justify its use or mean it is safe to ignore these warnings.
I can start a web page and recommend everyone put whale snot on their cartridge cases but the problem is you will NOT find any written material from any ammunition manufacture, reloading manuals or any reliable source telling you to put whale snot, grease, oil or ANY kind of lubrication on any ammunition.
The purpose behind dry oil free ammunition and a dry oil and grease free chamber is to allow the cartridge case to grip the chamber walls and reduce bolt thrust when the ammunition is fired.
Making excuses does not change the fact that your oiling and greasing the cartridge cases will double the bolt thrust, double the strain on the action and more than double the wear on your rifle.
The rubber o-ring method of fire forming cases does NOT require oiling or greasing the cartridge case and does not increase bolt thrust, strain or wear on your rifle.
As I said in the other forum ireload2, please produce any written material from the H.P. White testing Laboratories, reloading manuals or ammunition manufactures telling anyone to grease or oil their ammunition before firing it in their firearms.
Sierra Bullets FAQ:
Question
I don't want to waste my time wiping all the sizing lube off my cases after the resizing operation, but I've been told not to tumble loaded ammunition. Won't some lubrication help the cartridge chamber more easily? What happens if it is not removed before shooting?
Answer
Upon ignition, the case expands in all directions, with the case walls tightly gripping the chamber. Almost instantly, the case relaxes its grip on the chamber walls as the pressure starts to drop, allowing the case to be extracted. If the cartridge were lubricated, the case wouldn't be able to grip the chamber walls, allowing it to slam back sharply against the bolt face. In extreme examples, this force, called "bolt thrust," can even damage a firearm. For what it's worth, the British used to use lubricated cartridges to proof test a firearm, rather than the so called "blue pill" loads used here in the US. Wipe those cases, and make sure your chamber stays clean and dry!
Note: The British oiled proof cartridge was used to seat the locking lugs and bolt head because of the additional thrust it exerted. After proof firing the Enfield rifle was checked with a .067 headspace gauge and if the bolt closed on this gauge the rifle failed proof firing due to excessive set back of the lugs and bolt head.
Now what do you think a steady diet of greased and oiled ammunition is going to do to your Enfield rifle.
To quote EH - your own post
>>>I have used the resizing lube method in the past with many different caliber cases, but if you remember what Peter Laidler said about why the Enfield bolt heads only go up to #3 because by that time the case hardening has worn through and the Enfield rifle should be sent for overhaul or scraped because of receiver wear.<<<<
Decided you made a mistake once but you are right now?
Citation for this ???
>>>>
Note: The British oiled proof cartridge was used to seat the locking lugs and bolt head because of the additional thrust it exerted. After proof firing the Enfield rifle was checked with a .067 headspace gauge and if the bolt closed on this gauge the rifle failed proof firing due to excessive set back of the lugs and bolt head. <<<
So what head space was the rifle required to have before testing? What percentage ever failed proof testing. There is a lot of information missing.
What was the standard British proof test used for LE rifles. Is it the same proof stamped on the rifles? Why weren't the locking lugs pre-seated rather than depending on a proof load.
Citation- proof of this assertion???
>>>>Making excuses does not change the fact that your oiling and greasing the cartridge cases will double the bolt thrust, double the strain on the action and more than double the wear on your rifle.<<<
>>>Now what do you think a steady diet of greased and oiled ammunition is going to do to your Enfield rifle.<<<
Same as all my other rifles including Mausers, commercial hunting rifles,
Highwall target rifles------absolutely nothing.
BTW you said you used oiled cases yourself. What kind of damage did that do to your rifles?
I have asked a number of questions here. If you respond do you think you could answer any of them? I did answer your question.
The machine gun principle is a red herring in the debate on 303 bolt action rifles. Different beast different action different solutions.
One poster reported that his 500 rounds of superior quality HXP brass showed no thinning of the web ---after being fired in a machine gun.
Now is the issue the damage to the rifle or damage to the brass?
A number of countries had no problems oiling cartridges for use in machine guns.
Are machine gun barrels inherently stronger than rifle barrels?
It does illustrate that oiled cartridges are not instant destruction to gun mechanisms. On top of that a machine gun may fire more rounds in 5 minutes than are ever fired in any bolt action infantry rifle in combat. The chance for the oil to cause problems is much greater if it is a real threat.
The problem with the internet and gun forums is we have too many people who think they are firearms engineers and they can write or say anything they want.
It is quite obvious that ireload2 doesn’t like being wrong and he will say anything in his defense, as I said before show me any written material from any ammunition manufactures, H.P. White test laboratories, reloading manuals or any reliable source telling you to put ANY kind of lubrication on any ammunition.
You can’t do ireload2 you have no written verification from any notable reliable source and lubing cases is a shade tree home remedy that increases bolt thrust and damages firearms.
And ireload2 you DID NOT answer the main question, you did not supply any reliable written data telling anyone to grease or lube cases before firing.
What you did prove is you came here to argue about something YOU can’t verify or prove with any written material because YOU don’t have any.
The problem with amateur internet firearms engineers is they can’t read or do not understand what they read.
https://www.milsurps.com/images/impo.../oillube-1.jpg
Your posting keep getting progressively more desperate ireload2, if the machine gun was designed from the onset to fire lubricated cartridges then the increased bolt thrust was compensated for in its design criteria and the appropriate components strengthened to take the increased thrust.
What YOU are telling us is to ignore the warnings in the books and manuals and trust your internet engineering expertise. :rolleyes:
https://www.milsurps.com/images/impo...DANGER58-1.gif
What many you are missing here is ireload2 and another person wanted to argue about a thread I started at Gunboards using rubber o-rings to fireform cases and got the thread locked down TWICE.
And now ireload2 is here starting it all over again, this thread had been inactive for over 30 days until ireload2 reopened the thread for the sake of arguing further on claims he CAN NOT back up with printed data.
Fire Forming Cases W/Zero Headspace - Gunboard's Forums
Even at Varmit Al’s where he studies case and chamber friction he has a warning at the bottom of his chart warning about lubricating cases.
https://www.milsurps.com/images/impo...friction-1.jpg
OK, here's one -Quote:
Originally Posted by Edward Horton
https://www.milsurps.com/images/impo...ag42lube-1.gif
The AG42 Ljungman is a interesting case. It's a locked-breech, gas-operated semi-auto with a direct-impingement gas system and relatively small locking surface at the rear end of the bolt. Perhaps most germane, the Swedish military saved fired cases for re-use. The rifle's operation is fairly violent with Swedish ball cartridges and extractor breakage is a problem with dry ammo. Lube helps preserve the extractor - and the cases.
Based on the size of the locking lugs, receiver/bolt cross-section, and the distance from bolt face to locking surfaces, it's probable the Ljungman's raw action strength is not very different from a Lee Enfield. The cartridges, 6.5 and .303, also operate at very similar pressure (about 45,000 c.u.p. by US-style radial crusher). It seems case/chamber lube does more good than harm in the Ljungman. Certainly worked in mine.
Again, none of this means anyone should fire lubed cases in their Lee Enfield rifle. It's just some added information to help folks make their own decisions.
The Lee enfield requires a certain amount of friction grip between the case and chamber to reduce bolt thurst, oiled cases where used to limit the friction to check to see if the lugs were correctly where they should be before the Goverment inspector passed the rifle for Goverment ownership. British Goverment requirement. Machine guns do not require that friction many will not operate with sticky cases hence oil on cases.
The AG-42 Ljungman was a gas operated rifle designed from the ground up to use 6.5x55mm lubricated ammunition and the Model 1894, Model 1896 and Model 1938 Mauser type manually operated bolt action rifles did not require lubricated ammunition and were designed to operate without the use of lubricated ammunition.
The key words here are designed to operate “with” or “without” lubricated ammunition and NOT “I think it is OK” to use lubricated ammunition with its increased bolt thrust.
Ag m/42
The Automatgevär m/42 (Ag m/42) (outside of Sweden commonly known as the AG42, AG-42 or Ljungman) is a Swedish semi-automatic rifle in limited use by the Swedish Army from 1942 until the 1960s.
Operation
The Ag m/42 is operated by means of a direct impingement gas system, similar to that of the French MAS-49 and American M16 rifles. The Ag m/42 also uses a tilting breech block like the Tokarev SVT-38 / SVT-40 and FN FAL rifles.
The Ag m/42 uses the 6.5x55mm cartridge loaded into a removable 10-round box magazine. In practice, however, the magazine usually remains attached to the rifle while it is loaded from the top with five-round stripper clips. Like the British Lee-Enfield and Soviet SVT-40, the Ag m/42's magazine was intended to be removed only for cleaning.
Use caution when firing the Ljungman and Hakim rifles as the burn rate of the powder has a dramatic effect on the operation of the rifle. There have been reported cases of catastrophic failures of both these rifles when fired with incorrect ammunition. Even the Swedish m/41 ammunition was required to be lightly oiled by Swedish troops prior to loading as the burn rate of the powder is too slow and the oiling of the cartridge body facilitates extraction.
The main dynamic involves the pressure curve and the timing of the pressure curve as it relates to the location of the gas port in the barrel. While the Hakim has a gas port adjustment the Ljungman does not. As the bullet passes the gas port the gas pressure is channeled back to the bolt carrier to unlock the bolt. With a powder that is too slow a burn rate the bolt carrier opens violently prematurely and at an extremely excessive pressure. This causes the extractor to tear the rim off the cartridge case exposing the action to the dumping of very high pressures which typically exits the action downward into the magazine well, blowing the magazine completely out of the rifle and often destroying the magazine and stock in the process. Close attention must be paid regarding the use of correct ammunition in these two rifles.
Ag m/42 - Wikipedia, the free encyclopedia
Sometimes I wonder what people are thinking when they decide to cheat and bend the rules on gun design and cause possible gun damage and accelerate wear on a rifle designed to shoot ammunition that is not lubricated..
The Enfield rifle has already been labeled “an inherent weak design” and an action that flexes due to its rear locking lugs, WHY on earth would anyone want to lubricate a cartridge case in the Lee Enfield rifle and cause TWICE the force to be delivered to the bolt face and twice the damage and wear this rifle was designed to receive is beyond me.
I spent the last 25 years of my career as an Inspector at a military overhaul depot and it never fails to amaze me how many people ignore warnings and instructions in the manuals because they “think” they are “smarter” or “know more” than what is printed in the manuals.
97% of all errors are human errors and only 3% are actual mechanical failures and egos and assumption are the major cause of mechanical breakdowns and component failures and this is what causes aircraft to fall out of the sky.
https://www.milsurps.com/images/impo.../oillube-1.jpg
https://www.milsurps.com/images/impo...ssstrain-1.jpg
I am beginning to think that there are vested interests at work on this thread to keep the focus off the issue of either brass composition used in case manufacture or the manufactureing method used which is causing a problem with head separation in some Lee Enfields.
Bindi2
Our American or SAAMI made .303 cases could be made correctly to these standards and the larger chambers of the Enfield could be directly responsible for the short case life. BUT I think other factors could have something to do with the short case life when reloading.
Most of my questions are related to and come from reloading commercial ammunition in my Springfield 03-A3 with its corresponding larger military chamber and headspace and the 30-06 cases lasting far longer than currently made .303 cases.
The problem at Gunboards was my postings concerning cases life, chamber pressures and reloading methods kept getting locked down or the entire post deleted because of arguments from our online internet engineers.
What bothers me the most is the set piece standard answers about the “inherent weak design” or the “action flexing” on the Enfield and the fact no one wants to think outside the box and look at other contributing factors on case life.
And then to add insult to injury when your posts on fire forming cases using o-rings are hijacked by cartridge case oilers, who think they are the only ones in the world who know how to reload, you never get anything accomplished on the subject.
When I look at a 2002 Canadian Enfield manual and see headspace standards that are written for a cartridge case that is to be fired once, which translates to .064 GO, .070 NO-GO and .074 Field I wonder what has changed and why.
(I keep thinking it might be the brass case and the standards used to make them)
https://www.milsurps.com/images/impo...eadspace-1.jpg
#4 MK1 Lee Enfield bolt and receiver deflections at a given PSI
These are real numbers.
These numbers can be duplicated in Excel if you are interested.
The formulas and techniques are readily available on the internet.
All dimensions are in inches, pressure in PSI.
Note the deflections translate into stretching of the pressure ring
when the case body adheres to the chamber wall and the case
head is pushed against the bolt face.
I personally think it is poor practice to use case head stretch as a mechanical brake to minimize load on the action. Everyone that cleans a gun usually fires a shot or two with oil in the chamber each time they go to the range.
.......................Receiver.......Bolt........ .Total Deflection***
...PSI............... Stretch....Compression Receiver+Bolt
30000................0.0009.......0.0037.......0.0 046
35000................0.0011.......0.0043.......0.0 054
40000................0.0013.......0.0049.......0.0 062
41440................0.0013.......0.0051.......0.0 064
45000................0.0014.......0.0055.......0.0 069
50000................0.0016.......0.0061.......0.0 077
55000................0.0017.......0.0068.......0.0 085
60000................0.0019.......0.0074.......0.0 093
65000................0.0020.......0.0080.......0.0 100
70000................0.0022.......0.0086.......0.0 108
75000................0.0024.......0.0092.......0.0 116
80000................0.0025.......0.0098.......0.0 124
85000................0.0027.......0.0104.......0.0 131
90000................0.0028.......0.0111.......0.0 139
95000................0.0030.......0.0117.......0.0 147
Do you have citations for your assertions?Quote:
Originally Posted by Bindi2
What is the certain friction grip? Is it quantified? What happens if you clean your and oil you gun with PTFE lubes?
This friction grip is modified by polishing your brass. It can also be modified by polishing your chamber. Are you also implying that you should not polish your brass or the chamber?
All rifles inevitably get fired with some oil in the chamber.
Are you saying this will damage a Lee-Enfield?
Is that why Lee-Enfields seem to have such gross headspace?
Do you have answers for any of this?
Posted by EH
>>>Springfield 03-A3 with its corresponding larger military chamber and headspace and the 30-06 cases lasting far longer than currently made .303 cases.<<<
You can easily measure the Springfield receiver and bolt that permit you to calculate the stretch of the receiver and the compression of the bolt.
If you will do this once for the Lee-Enfield and once for a front locking bolt gun you will have a lrge part of your answer. There is no magic.
Posted by Parashooter.
>>>I believe those who assert that radial expansion contributes to the kind of head separation commonly encountered by .303 reloaders are mistaken. Radial expansion puts the circumference of the solid case web in shear, not stretch - and it does so in a completely different location.<<<<
The case pressure ring material has to stretch radially until it it constrained by the chamber. There is some bending since the stretch occurs at an angle due to the proximity of the solid head. However this still results in the pressure ring being stretched buy the difference in diameter of the case and the chamber as well as the forces that stretch the case along it's longitudinal axis. Stretch along the relatively long longitudinal axis has the opportunity to get spread over a long portion of the case length. The radial stretch that occurs to the pressure ring area is concentrated over a short distance increasing it's damage to the case wall. If there was no stretching caused by the difference in diameters it would be possible to use a much smaller cases head with no consequences. We know that is not possible.
[QUOTE=Edward Horton;54858]Sometimes I wonder what people are thinking when they decide to cheat and bend the rules on gun design and cause possible gun damage and accelerate wear on a rifle designed to shoot ammunition that is not lubricated..
The Enfield rifle has already been labeled “an inherent weak design” and an action that flexes due to its rear locking lugs, WHY on earth would anyone want to lubricate a cartridge case in the Lee Enfield rifle and cause TWICE the force to be delivered to the bolt face and twice the damage and wear this rifle was designed to receive is beyond me.
I spent the last 25 years of my career as an Inspector at a military overhaul depot and it never fails to amaze me how many people ignore warnings and instructions in the manuals because they “think” they are “smarter” or “know more” than what is printed in the manuals.
97% of all errors are human errors and only 3% are actual mechanical failures and egos and assumption are the major cause of mechanical breakdowns and component failures and this is what causes aircraft to fall out of the sky.<<<
Interesting to think that an inspector thinks he knows more about the rules than the engineers that make them.
All errors are human errors. BTW manuals are full of errors. Even inspectors have an error rate. The only way to stop errors is to kill all the people. :lol:
You lubricate the case so you don't use the case as a mechanical brake.
Using the case as a mechanical brake guarantees damage to the case. To avoid damage to the action reduce the loads. You can't stop it from flexing.
Dear All, let's keep calm.
I am getting worried. I am trying to learn something from other people who have knowledge that I do not possess, but have the increasing feeling that merely asking why or how is sufficient to cause offense. If that is the case, then the forum will not function in the sense of a profitable exchange of ideas and information.
I am grateful to be able to read contributions that provide facts and experience that I do not have and cannot otherwise acquire. I was a development engineer and then head of a development laboratory in a very large international company for many years. An activity that requires that you know the book, before you start, but also that you are prepared to investigate some of the assumptions in the book, without that being considered frivolous or those who wrote the book becoming offended. I would like to see the forum progress in this spirit
In the case of the rear-locking bolt construction of the Enfield, I am charmed by the brilliant simplicity of the O-ring method, and will try it out when the competition season has tapered off.
But a thought occurs - assuming that ireload2 has used the correct modulus of elasticity etc, then we are faced with the following limitation: even if we have an Enfield action with a zero headspace, then, if the case head remains in contact with the bolt head, the case head will be pushed back as the bolt is compressed, and then pushed forward as the pressure drops. So a case that has been held up against the bolt face with an O-ring will, after firing, have undergone a rapid cycle of stretching and compression by the amount of the bolt compression, even if all other play is zero.
In other words, the rear locking bolt system is going to strain the case even if there is a perfect case-chamber match. And the only way to reduce that effect is to reduce the pressure peak. So while I am sure that the O-ring method is a very good idea to reduce the cartridge strain, and should therefore increase case life, there will still be a strain cycle that will, eventually, cause the cartridge to fail. It would therefore be interesting to hear if there is any data on 303 cartridge life using the O-ring method.
Patrick
If this were true, we'd expect cases to separate at the junction of solid web and hollow body. However, they don't. They chop at some distance from obvious point where the body has expanded to meet the chamber. Nice theory, but the physical evidence seen in a typical separated case just doesn't seem to support it.Quote:
Originally Posted by ireload2
https://www.milsurps.com/images/impo...3sephead-1.gif
Hi Patrick,
The modulus used for steel is 30E6.
I used .390 as the inside diameter of the case assuming .030 wall thickness and a .450 case head diameter.
Bolt OD = .580
Bolt ID = .385 Actual measurement.
The loaded lengths were measured directly from a rifle
The receiver rails were measured as a set of small rectangles and triangles to calculate the receiver area in tension.
I don't doubt the O ring helps.
If the elastic limit of the brass is reached by the expanding and stretching due to head space and action elasticity then the case will be permanently deformed (stretched). This deformation is marked when comparing a front locking bolt gun to a Lee-Enfield. Assuming equal pressures it makes for markedly different case life.
Parashooter,Quote:
Originally Posted by Parashooter
You fail to see that the failure is not all due to longitudinal stretching or radial stretching. It is the combined stretching that you see.
You don't go from a case head diameter of .450 to a chamber diameter of .460 for free. The brass has to stretch. The location of stretch is not right at the solid head because the brass wall is usually tapered. Because of the taper the stretch gets concentrated where the case wall radial stretch is greatest the case is weakest. That is usually (but not always) where the case contacts the chamber wall.
In my case the separation occurs right at the solid head not out like Paras photo. I have read the British and Australian manuals of the day and had the care of the L E drumed into me by the men who who carried repaired and used them. They did not have lubes ,case tumblers etc which are from a more modern time. Todays technology is not as good it appears to some bygone technolgy. Todays brass composition is either different or the manufactureing process is different to historical composition or manufacture.Quote:
Originally Posted by ireload2
Patrick Chadwick and Bindi2
Never trust anyone who thinks he is smart enough to rewrite the rule book and oils his cartridges before firing them.
https://www.milsurps.com/images/impo...ssstrain-1.jpg
https://www.milsurps.com/images/impo.../oillube-1.jpg
Never trust anyone who uses the assumption that everyone leaves oil in the chamber to justify oiling his own cases before firing.
https://www.milsurps.com/images/impo.../drybore-1.jpg
Never trust anyone who can give you the “exact” figures on how much your bolt will compress and your action will flex.
.......................Receiver.......Bolt........ .Total Deflection***
...PSI............... Stretch....Compression Receiver+Bolt
30000................0.0009.......0.0037.......0.0 046
35000................0.0011.......0.0043.......0.0 054
40000................0.0013.......0.0049.......0.0 062
41440................0.0013.......0.0051.......0.0 064
45000................0.0014.......0.0055.......0.0 069
50000................0.0016.......0.0061.......0.0 077
55000................0.0017.......0.0068.......0.0 085
60000................0.0019.......0.0074.......0.0 093
65000................0.0020.......0.0080.......0.0 100
70000................0.0022.......0.0086.......0.0 108
75000................0.0024.......0.0092.......0.0 116
80000................0.0025.......0.0098.......0.0 124
85000................0.0027.......0.0104.......0.0 131
90000................0.0028.......0.0111.......0.0 139
95000................0.0030.......0.0117.......0.0 147
https://www.milsurps.com/images/impo...friction-1.jpg
Never trust anyone who tell you his ideas are always better than anyone else’s.
https://www.milsurps.com/images/imported/deleted.gif
And NEVER trust anyone who thinks he is smarter than the Sierra reloading manual.
https://www.milsurps.com/images/impo...can0048a-1.jpg
And just to make sure everyone is treated fairly here, NEVER ever trust anyone who thinks he knows more than Parashooter. It is sometimes and only rarely permissible to disagree with Parashooter on minor issues and procedures but one should NEVER criticize Parashooter on everything.
(The odds aren’t in your favor)
Personally I like the way I greased this one into the thread. :D
(After all caster oil is considered medicinal) :rofl:
Patrick, a spacer (O-ring or other material) is useful on initial firing of new brass because it eliminates/reduces the component of case stretch due to cartridge end-play. The benefit is minimal if end-play is small, but can be significant when thin rims and/or generous headspace give the new case substantial end-play (more than .010" or so). As you note, it cannot eliminate the portion of case stretch due to action flex - but that is generally a minor element compared to end-play. I'm afraid reduced pressure and/or the presence of lubricant are the only readily-available solutions to stretching caused by action flex. Heavy-walled cases can last longer simply because they can stretch more before breaking.
My friend Mr. Horton - no irony, I enjoy our jousts - has shown us a number of authoritative warnings about lubricated cases and/or chambers. I appreciate the value of emphasizing and distributing them. Keeps some reckless folks out of trouble. On the other hand, I long ago learned to distrust (or resent) authority. For instance, I don't obey the many warnings I see about wearing seat belts. Nevertheless, I've never been injured in a car wreck - probably because I'm a very defensive and reasonably competent driver with a good measure of dumb luck. Seems to me some of the cautions we encounter might not be so absolutely imperative as they are purported to be. (Or maybe I'll fly through the windshield tomorrow.)
Believe nothing, no matter where you read it, or who said it - even if I have said it - unless it agrees with your own reason and your own common sense.
-- The Buddha
Ireload2, I now understand what you're getting at concerning radial expansion combining with axial to produce case thinning. It's certainly true, but if you'll do the math you'll find that thinning from radial expansion, spread over the entire circumference of the case, is minor (only about 2% when we expand from .450" to .460" diameter, for example - and only on initial firing unless we FL size), while axial stretching, confined to a narrow band (about .1" wide at most) somewhere ahead of the transition between wall and web, is much more significant and accounts for virtually all the cumulative thinning resulting in eventual separation.
Occasionally, of course, radial expansion is not evenly distributed around the circumference of the case. When that occurs, we see axial body splits ahead of the web, like the 4th example below -
https://www.milsurps.com/images/impo...asefail2-1.jpg
>>>radial expansion, spread over the entire circumference of the case, is minor (only about 2% when we expand from .450" to .460" diameter, for example - and only on initial firing unless we FL size), while axial stretching, confined to a narrow band (about .1" wide at most) somewhere ahead of the transition between wall and web, is much more significant and accounts for virtually all the cumulative thinning resulting in eventual separation.<<<
Please show us the number that you base the 2% upon.
I guess I disagree with your conclusion. When the entire .010 difference in diameter is accommodated by localized stretching of a case the amount of stretching .010 is significant to the thickness of the brass - normally near .030 thick.
Let me use a couple of extreme example.
1. What is the usual result of firing a 7.62 Nato round in a .30-06.
You get a blown out .308 case with no neck. There is usually no separation reported even thos the .308 case had little real headspace control.
2. What happens when a .270 is fired in a 7mm magnum?
Usually the rifle is wrecked because the case could not handle the radial stretching.
These are extreme example of case missfits but they serve to show the critical nature of having the case head fit the chamber closely.
There is another example of case to chamber misfit that exists with the 6.5 Arisaka. The Type 38 rifle is know to be very strong. It would exhibit very little spring with high pressure loads. After the first fire forming load it would have a fit from head to should to control the headspace. Yet ammo fired in these rifles give head separations due to the thinning of the brass where a huge step is formed due to the mismatch of the case head and the chamber.
One of my reasons for focusing on radial thinning is that on a an experimantal basis it is possible to use brass to eliminate most of it. By using larger brass you are left with only axial stretching forces.
Just FYI
Quote from VarmintAls
About half way down the page
CONTROVERSY OR GOOD ENGINEERING.... Now some controversy. I polish my chambers with Flitz. I don't want excessive friction between the brass and the chamber wall. Some are going to argue with this, but I have thought long about this. I have tried it and it works and is good engineering. I polished the chamber in my new Virgin Valley (no longer in business) barrel and it has made quite an improvement. With a polished chamber, the friction coefficient is much less between the brass and the polished stainless steel chamber. The pressure is able to force the case head against the bolt face before the case walls grab the chamber. First, this lets the primer (on the first shot with new brass) protrude, but be immediately reseated in the primer pocket as the case head is pushed back. The brass does not stretch nearly as much as it would in a rough chamber. Now some will say that a polished chamber will increase the force of the bolt face (frame face on the Encore) and that is bad. WRONG! That is faulty logic. The force is increased on the bolt face, but that is where it belongs. As all modern rifles, the barrel and frame of the Encore are designed for strength. They are strong enough to support large diameter Magnum-belted calibers. The force from the much smaller area of the .223 case head is easily supported by the frame face. The brass case is designed to act as a bladder and encase the gas pressure. Trying to use the weaker brass to lighten the load on the action and bolt face of a rifle by having the brass grip the chamber is analogous to using a car's radiator to protect the bumper in a front-end collision. A polished chamber minimizes case stretching, reduces case head separation, and increases case life. More information on chamber finish here. To polish a chamber, I put Flitz on a cotton bore mop and a piece of cleaning rod long enough to be held in a drill motor. I polish for about 30 seconds or more at a 300 to 600 rpm speed. Sometimes I have to wrap a paper towel around the swab and put Flitz on it to get a good fit. Be sure that the end of the bore mop's metal part is much smaller than the bore and covered so it will not damage the rifling in front of the chamber.
It has been said that oiling a case so that it does not adhere to the chamber is bad. That it damages the Lee-Enfield rifle. That it is counter to all the manuals. It is implied that the Lee-Enfield and all other rifles depend on the friction from the case to prevent damage to or over loading of the action.
So I will ask the following question.
If the case head is flush against the bolt when fired the bolt takes all the load right...That is all the load until the LE starts to stretch. Then the walls of the case begin to act as a brake connecting the case head to the chamber walls.
As the LE action stretches the case walls are stretched also until one of two things happen.
1. The pressure subsides
2. The case head separates
In case one the pressure subsided before the case was stretched enough to rupture. However the case was stretched since the LE action is not rigid.
In case two the case is stretched past its yield point and ruptures.
When it ruptures the brake formed by the case walls adhering to the chambers instantly disappears and the full load of the chamber pressure hits the bolt face.
Which is the worst case (no pun intended)?
A. An oiled case that is able to slip past the chamber and take up less of the load on the action while protecting the case walls against rupture.
B. A case that adheres to the chamber until it almost separates or separates putting the full load of the chamber pressure against the bolt face?
>>>Never trust anyone who can give you the “exact” figures on how much your bolt will compress and your action will flex.<<<
Design engineers use these same mathematical formulae to evaluate their designs before comitting them to metal for testing. Certainly my numbers are vastly more accurate than NO numbers.
These calculations are relatively simple and can be completed by anyone with simple math skills.
Deflection = (Force X Length) / (area X Young's modulus)
Force = PSI of chamber pressure X the internal surface area of the case head normal to the bore
area = the cross section area of the component under load.
Young's modulus = a known value for steel = 30,000,000
In the case of the LE action the bolt is compressed and the receiver is stretched by the chamber pressure.
OK, here's how I get that 2% thinning from .010" radial expansion in a .303 -Quote:
Originally Posted by ireload2
https://www.milsurps.com/images/impo.../stretch-1.gif
- If the initial diameter of the case is .450", its circumference is .450"x pi = 1.413".
- If it expands to .460", the circumference is now .460 x pi = 1.445".
- The difference in circumference is 1.445" minus 1.413" = .032".
- .032 divided by 1.445 is .022 or 2.2%.
- The reduction in thickness of the case wall is directly proportional to the increase in circumference (To make this step easier for math-dummies like me to grasp, I imagine that we straighten out the radial section of the case into a thin rectangle 1.413" long and .030" thick. If we stretch it 2.2% longer, to 1.445", it must also become 2.2% thinner to maintain the same area. A simplified example is shown below.)
I've never had a problem with head separations in 6.5 Arisaka - but I habitually lube cases to reduce axial stretch. Same goes for 7.5 MAS and 6.5x55 formed from .30/06, where the parent case is about .015" to .020" undersize.
Because it has less body taper, 7.62 NATO chambered in a .30/06 chamber is normally a very tight fit at the shoulder, eliminating end play because the 7.62 is wedged firmly in place. If the chamber is oversize or the case undersize, the extractor holds the case close enough to the bolt face to keep axial stretch within limits - if it didn't, the firing pin couldn't reach the primer.
https://www.milsurps.com/images/impo...toin3006-1.jpg
Look closely and you can see the scratches where the former shoulder was forced into the chamber.
.270 Win. fired in 7mm Magnum has to expand from about .470" to .515", a 10% change in circumference. This can exceed the elastic limit of the brass case. (See http://www.engineershandbook.com/Tables/copperprop.htm and you'll find the elongation limit for cartridge brass in the "hard" condition we might expect in a case head is 8%. Or we could trust the table Ed provided earlier in this thread, with the same 8% elongation for "full hard".)
https://www.milsurps.com/images/impo...hardness-1.jpg
My definition of radial stretching is a bit different than yours.
First of all you described what I agree would be circumferential thinning.
What I call radial thinning it the big step the case has to form on one side when it is off center in the chamber. From .450 to .460 creates a step of material .010 tall. If you looked at a fiber of that material it would have originally be aligned axially how ever when dispaced at right angles to the case axis I call it radial stretching. This material was once a straight case side wall. When fired, suddenly .010 extra length of material has be stretched from a short area of the case body.
Consider the material is only .030 thick or so you have large amount of stretch concentrated in a small spot. That area rapidly becomes the weakest area on the case because of the additive nature of the axial and radial thinning being concentrated at the step near the solid head.
A lot of my case ideas are only tests to determine if improved head to chamber wall fit will significantly increase case life. They are not mean't to be anything more than educational at this time. If they do improve the case life a little there are a few other things that might help a little.
If all the things work maybe case life in the LE can be made tolerable.
Today I amde some cases out of .405 Win. The head dia is .458 and my chamber is .460. The cases weigh 195 grains the heaviest .303 creations yes.
The rim thickness was not the .074 predicted by EH's Hornady Manual page.
The rims are only .066 thick on avg. If the reims are too thick I know a very fast way to thin them for be an exact thickness for a given rifle.
I set the shoulder tight and I will lightly lube the cases when they are fired.
They will be compared against .444 Marlin brass and a wide array of others including Interarmco, Herters's, Norma, WRA 1943, FC , R-P and WW.
I expect the Marlin and the .405 Hornady brass will be long lived. I have no idea what will happen to the rest.
>>>>270 Win. fired in 7mm Magnum has to expand from about .470" to .515", a 10% change in circumference. This can exceed the elastic limit of the brass case. (See http://www.engineershandbook.com/Tables/copperprop.htm and you'll find the elongation limit for cartridge brass in the "hard" condition we might expect in a case head is 8%. Or we could trust the table Ed provided earlier in this thread, with the same 8% elongation for "full hard".)<<<
These split lengthwise down the side of the case. Since the case head is too small to form a good cup and seal the breach the gas escapes into the receiver of a BAR and blows out the magazine, swelling the receiver walls and partially splitting the for end.
.405 brass being formed to .303
https://www.milsurps.com/images/impo...om405JPG-1.jpg
Finished .303 formed and trimmed from .405
http://i14.photobucket.com/albums/a3...05brassJPG.jpg
.303 formed from .405 loaded
This brass is .458 at the head for .002 clearance in the chamber.
The .303 brass formed from .405 weighs 195 grains.
http://i14.photobucket.com/albums/a3...5loadedJPG.jpg
The reason they do the testing is because the math only gets them close, empirical testing gets them the rest of the way. In other words, the gun still don't work from the numbers and they still have to fiddle around with the thing to get it to work.Quote:
Originally Posted by ireload2
I did know one of the engineers at Stevens who'd convinced the government to allow the changes to the Thompson and Stevens so they could actually make some money on the low bid contracts. He said to me what I just repeated to you. I've confirmed it with other firearms engineers. The math only gets you so far.
And you are using math against a finished product. And a known value for steel that may not be the value for this steel.
Kinda like doing things bass ackwards.
Let’s see at least $45.00 for the .405 cases, then you have increased home owners insurance because Teddy Roosevelt is going to haunt you until you’re in the grave, time involved with multiple case forming steps, $60.00 for a neck turning tool and another $7.00 for a pilot (plus shipping) and a dump truck to haul the excess brass away.
Or you can fire form your cases with a .29 cent rubber o-ring and save all the man hours and $139.95 in miscellaneous expenses not counting all the oil and grease you need to fireform YOUR cases.
https://www.milsurps.com/images/impo...IMGP5098-1.jpg
https://www.milsurps.com/images/impo.../oillube-1.jpg
https://www.milsurps.com/images/impo.../drybore-1.jpg
https://www.milsurps.com/images/impo...ssstrain-1.jpg
https://www.milsurps.com/images/impo...can0048a-1.jpg
Oh and I almost forgot, you will need a special permit from the EPA for cleaning up an oil spill at your shooting range (Plus fines and court costs) :yikes:
https://www.milsurps.com/images/imported/deleted.gif
Yes, and the reason is that the radial (circumferential) elongation of approximately 10% exceeds the elastic limit of the brass in that part of the case.Quote:
Originally Posted by ireload2
My statement clearly says that engineers use the numbers to evaluate their designs before committing them to steel for testing. My numbers are only used to predict the deflection of the metal under a load. Therefore it uses only Young's modulus for steel. If you will take the time to review Young's modulus for steel you will find it is basically the same all steels. You can also find the drop dead simple equation used to generate these numbers. The deflections are real. The Lee-Enfield action is not as rigis as many presume.Quote:
Originally Posted by limazulu
Note it is not a measure of ultimate strength just the deflection under load. There is nothing bass ackwards about this at all.
>>>Let’s see at least $45.00 for the .405 cases, then you have increased home owners insurance because Teddy Roosevelt is going to haunt you until you’re in the grave, time involved with multiple case forming steps, $60.00 for a neck turning tool and another $7.00 for a pilot (plus shipping) and a dump truck to haul the excess brass away.
Or you can fire form your cases with a .29 cent rubber o-ring and save all the man hours and $139.95 in miscellaneous expenses not counting all the oil and grease you need to fireform YOUR cases.<<<
1. The cases were donated to me by another forum member. So it = $00.00 cost to me
2. I already own 7 neck turning tools and have access to a 13" engine lathe.
I have over 10,000 hrs spent running various lathes so turning the cases was no extra cost. I turn cases for other rifles so no big deal.
3. No new pilot was required I just used a .308 benchrest pilot. Who do you know that has benchrest quality brass for their .303 ?
4. I predict that the tonnage of brass hauled away will be less with .405 brass compared to using brass with undersize case heads that comply with the British standards. One separated case is more waste than trimming 50 cases.
5. I would also be glad to try your O rings recommendations. However when I asked you for the O ring size that you use you ignored my request. You have also ignored repeated requests for case life data using your O rings.
Since it has not been supplied I assume it does not exist.
I have no beef with your O rings but they will never cure the effects of the designed in mis-match between the case head diameter and the chamber diameter. Use of the .405 brass will tell me how much difference that clearance makes. In addition the thicker rim of the .405 fits my rifle like it was made for it. It must be the ghost of TR watching over me.
Let's see, we chose between a little extra oil on the case or all that gas you burn going to the parts house to buy O rings that eventually wind up as landfill material.