Does anyone have a fully dimensioned drawing of the .303 British maximum cartridge as standardized to be fired in Lee-Enfield rifles?
I need the max cartridge drawing so I can compare it to the minimum standard .303 rifle chamber. Thanks
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Does anyone have a fully dimensioned drawing of the .303 British maximum cartridge as standardized to be fired in Lee-Enfield rifles?
I need the max cartridge drawing so I can compare it to the minimum standard .303 rifle chamber. Thanks
Moderator Edit: Fixed pic links for member so they would display properly ... ;)
Thanks for posting the pics Zippy7.
I have a little difficulty in interpreting these two drawings.
Pic without bullet: case length 2.22"
Pic with bullet: case length 2.222"
Fairly closely the same, and plausible if the pic without bullet represents the maximum case dimensions.
The shoulder angle is 16.6 in both cases, but:
Pic without bullet: base-shoulder 1.786", neck length 0.304, shoulder 0.393"
Pic with bullet: base-shoulder 1.790", neck length 0.332", shoulder 0.401"
If the pic without bullet represents the maximum cartridge, and the pic with bullet is the minimum chamber, then I am worried by the max neck diameter being 0.339" and the minimum chamber (at the neck) being 0.338". And the 0.304" neck length seems plain wrong. Perhaps someone could help me with the interpretation of these drawings?
I am not being just picky here. There has been such a lot of heated discussion of Enfield cartridges in the past on this and the old CMP forum, in the course of which a couple of contributors managed to get themselves banned, that I feel it is important to be sure that any data presented are correct (as far, of course, as the contributor can judge).
This requires stating the source of such information and, if possible, the date of the drawing. I suspect that the maximum dimensions may have altered over the decades. All I know for certain is that the base-shoulder distance on my arsenal-mint (i.e. banged around in storage, but otherwise apparently unused) examples of a No. 1 MKV and No.4Mk2 do not match in this respect, and in both case the shoulder is much, much deeper than on cartridges formed in modern sizing dies. I live with this by segregating the cases for the two rifles and neck-sizing only (yes, I even have two sizing dies, for this very reason).
So I too would like to know what the "real" British standards were, at a given time. But from official drawings - if anyone has such.
Patrick
The .303 is a little like sausage -mystery meat.
With the abundance of British documentation it seems like a British military standard format drawing would be available. This needed drawing should show the maximum permissible cartridge dimensions for easy comparison to the smallest permissible chamber dimensions.
I'm not sure what else is in these two old scanned books, but about 500 or so pages into the 1915 version, there's several pages discussing the .303 cartridge, including color plates.
The two "out of print" books can be found in the Technical Articles for Milsurp Collectors and Re-loaders (click here)
http://photos.imageevent.com/badgerd.../treatise3.jpg(Copy PIC to Enlarge)http://photos.imageevent.com/badgerd.../treatise4.jpg
1905 Treatise on Ammunition (click here)
1915 Treatise on Ammunition (click here)
Regards,
Badger
It seems logical that SAAMI drawings are based on specifications provided to US manufacturers by British sources. After all, US firms produced many millions of rounds for the British government during various conflicts and it would have been embarrassing if they didn't work in British arms.
Certainly the chamber specifications are pretty close.
https://www.milsurps.com/images/impo...ommongif-1.jpg
Just going by the dimensions of fired cases from multiple examples of weapon types, there's several "families" of 303 SAA chambers. Whether the CARTRIDGE dimensions changed over time, well, that's an issue better left to cartridge collectors.
Weapons w/ similar chamber dimensions:
1.SMLE- British, Indian, Australian
2.Pattern 1914
3.Ross (Small)
4.Ross (Big)
5.No.4 Mk.I, No.4 MkI*, No.4 Mk.2, BREN
Not enough samples of other types to make any guesses. I'm not saying they're exactly interchangable, just close, from weapon to weapon.
I DO have several SMLEs and No.4s that can interchange neck sized reloads i.e. - SMLE to SMLE, that's what got me to checking.
JM,
Do your chamber shoulders remotely resemble the shape of unfired ammo?
Very good Parashooter. The top drawing is the first one I have seen with any tolerances. Looks like a plausible specfication drawing (at last!). Could you please give us a source reference?
The second drawing illustrates the problem. The (presumably minimum) chamber depth to the end of the neck is given as 2.158".
But in the top diagram we can read the corresponding dimension as 2.222 (presumably absolute minimum) minus the maximum recess for the rim (0.071") = 2.151. You will only get the 2.158" with a minimum rim recess!
So if you are one of those who like to leave the cartridge as long as possible, and chamber a cartridge that is more than 2.151 long beyond the rim, for instance because the OAL is OK, but the rim has the minimum thickness, then you may be getting a neck jam when the firing pin rams this cartridge forwards.
Not good for pressure, I believe. An example of how a derived drawing that leaves out tolerances can lead to grave problems of interpretation.
Take that maximum rim recess of 0.071", combine it with the minimum rim thickness of (0.064-0.010")=0.054" and you have a head clearance of 0.017" plus any gap between bolt face and back of chamber when firing those actual cartridges in that actual rifle. Similar effect at the shoulder, but it is getting late over here and someone else can check it out.
Ireload 2, I think I know what you mean by the shoulders. I have a lot of PMC cases. The first time I looked at the fired cases, the shoulder had been reformed so far forwards that, thinking the cases would be to spec. I wondered if my No. I MKV had been rechambered to .303 EPPS. Not so of course, it is the cases that must have been made to the absolute minimum dimensions. See the drawing posted by Parashooter.
Maybe I'll check it all through tomorrow, if someone else hasn't already done so, but it seems to me that cartriges made to absolute minmum specs are going to have an awful lot of space at both ends on first firing.
No wonder that those minimum-dimensioned cases are heavily strained on firing, and no wonder that if they are then reformed in dies which are probably also made to minimum dimensions (so that resized cases fit all possible rifles) and fired again that they will not last long.
In the end, it all comes down to the only sensible practise for old service rifles, where specifications are hazy or non-existent, and rigid compliance with those specs is also questionable after a century of use - after first firing, only use neck sizing, and only use those cases in the same rifle in which they were first fired. For anyone firing original BPCRs (one of my favorite activities), where the cases cost several dollars or euros each, this is so obvious that it need not be discussed.
So I advise everybody to stop worrying about specifications of arguable origin, validity and applicability, and simply form their real brass to fit their real rifles, not theoretical values. I am intrigued by the theory and the engineering problems that have been thrown up in this thread, but I also want to shoot my rifles!
Patrick
Patrick,
Many BPCRs (and all those I shoot) have little to no effective shoulder.
The 45-70 is one that I have fired thousands of rounds through using relatively few cases. I have never had a case head separate on a BPCR. I have had them burn through with a pin hole and have had the necks split.
BTW the bullets are always lubed with lots of gooey lube and at times it gets all over the cases and chambers with no ill affects using smokeless powders.
ANSI/SAAMI industry standards for the manufacture of firearms and ammunition.
Item #206 Z.299.4 1992
ANSI/SAAMI Centerfire Rifle
(Page 63)
"Chamber Full Size" drawing provided by E.Horton. Original source?
Unless too far forward for easy chambering, shoulder position is largely immaterial with rimmed cases in sound arms. Contrary to beliefs often stated, rimmed case unsupported at shoulder does not "blow forward" and elongate, but rather expands radially - and shortens. (Elongation occurs primarily during full-length sizing of expanded fired cases, added to any sidewall stretch resulting from end-play before firing with case and chamber clean.)
https://www.milsurps.com/images/impo...xialdemo-1.jpg
45-70 chamber pressures:
Trap Door 1873 Springfield = 18,000 CUP
1886 Winchester & 1895 Marlin = 28,000 CUP
Ruger No.1 & No.3 = 40,000
I didn’t grease my cases or bullets for my 45-70 Ruger No.3 when I was shooting 300 to 500 grain jacketed bullets at 40,000 CUP.
Normal chamber pressure with black powder and the 45-70 is 18,000 CUP or less so case head separations would be a rarity. I never had a 45-70 case head separation in a dry chamber in my No.3 Ruger either.
When I shoot cast bullets my cases are NOT greasy and my lubed bullets are “inside” the case and crimped in place.
(bullet lube sealed inside the case where it belongs)
South African military surplus.
https://www.milsurps.com/images/impo...IMGP6317-1.jpg
The unfired South African cartridge in a Wilson case gauge (SAAMI chamber) .002 under minimum head space as required. The case rests and is head spacing on its shoulder and not the rim in this gauge. SAAMI cartridge case shoulders should be .002 shorter than minimum head space (even on a rimmed case)
https://www.milsurps.com/images/impo...IMGP6318-1.jpg
Fired case sticking approximately one eighth of an inch above the SAAMI gauge. This shows how much deeper the military Enfield chamber is compared to SAAMI or CIP chambers.
https://www.milsurps.com/images/impo...IMGP6321-1.jpg
Brand new Remington case in the Wilson case gauge, the case shoulder is a quarter inch too short and is blown out even further in the military Enfield chamber. (the case should be just .002 below the lip of this gauge)
https://www.milsurps.com/images/impo...IMGP5199-1.jpg
"So I advise everybody to stop worrying about specifications of arguable origin, validity and applicability, and simply form their real brass to fit their real rifles, not theoretical values. I am intrigued by the theory and the engineering problems that have been thrown up in this thread, but I also want to shoot my rifles!"
Patrick Chadwick :thup:
Theoretical and actual are two different things. ;)
Ed Horton
Not really, hence the various "families". But there's some little differences even in the ammo, however, I never catagorized them.Quote:
Originally Posted by ireload2
W/in a particular family, I have a few rifles that can interchange neck sized only rounds, but it's generally easier just to segregate by S/N. Which can be right annoying during a busy range day! I'm really starting to miss cheap "non-reloadable" surplus ammo....
Old quote from the engineering world:
"Theory is when it ought to work, but doesn't. Practice is when it works, but nobody understands how"
Patrick
In theory, theory and practice are the same. In practice they are not.
The theory that cases with a little bit of lube or oil will damage your rifle is just that. At one time or another all rifles are fired with a film of oil in the chamber.
BTW all my cast bullets, and there have been tens of thousands of them since 1972, have been lubricated grease groove bullets. In most of my loads there is/are exposed grease and grease grooves on the bullets. When fired some of the grease is left in the chamber and it leaves a film in the bore. It eventually gets on the case too. No big deal ever.
Parashooter is right about case shoulder expansion. The annealing halo remains in the same location and the shoulder blows outward unless the brass is very hard.
From the "1929 Textbook of Small Arms"Quote:
Originally Posted by ireload2
https://www.milsurps.com/images/impo...drawing2-1.jpg
https://www.milsurps.com/images/impo...awingjpg-1.jpg
https://www.milsurps.com/images/impo...4/TBOSA1-1.jpg
I have reloaded for a number of Lee Enfields. Fazakerley No 4 Mark 1 and 2, Long Branch No 4's, Lithgow No 1 Mk III's , and one Savage No 4 Mark 1*.
The shoulder profiles on the fired cases have any number of different shapes, from sharp angles to smooth curves. The shoulder distance from the base is as varied as the autumn leaves.
I gave up trying to measure headspace on these things as all headspace greater than my American gages.
About the only thing common to the chamber of these rifles is that they will fire factory ammunition.
Edward, that is a very interesting book cover. Looks like a Colt New Service revolver on the top right. But I can see the cylinder latch, which is on the left side of the frame on my revolver. And I think I can just about see the O as the next-to-last letter in the logo on the grips. Have my eyeballs finally given up, or is that truly a reversed picture of the New Service?
Patrick
PatrickQuote:
Originally Posted by Patrick Chadwick
I don't see anything wrong with the Colt New Service on the book cover. :rolleyes:
(you might want to have your eyes checked) :madsmile:
https://www.milsurps.com/images/imported/deleted.gif
http://i122.photobucket.com/albums/o...1/TBOSA-1c.jpg
Good eye Patrick ;)
Funny thing, that maximum cartridge drawing above. Check out the maximum base dimension.
Moderator.Quote:
Originally Posted by jmoore
Please delete Mr. jmoores posting and reduce his post count by 250, Mr. jmoore is drinking CNC cutting fluid "again" and has extremely blurred vision and can't see the SAAMI and British drawing are the same. :madsmile:
Mr. jmoore and Patrick
Please look at the SAAMI drawing again, base diameter of the SAAMI drawing is .4601, .200 forward of this the case diameter is .4554. The drawing from the "Textbook of Small Arms" is "maximum" allowable dimensions and is in the section of the book on "gauging" the Enfield, the base diameter in this British drawing is .460 or .0001 smaller than the American SAAMI drawing.
You are talking about one ten thousandths of an inch difference or 2.54 microns. :rolleyes:
Yep, it's way too fat.
That illustrates what I mentioned before - take a drawing, copy the dimensions, make a couple of mistakes, round a couple up or down - and hey presto! - we're all arguing our socks off about dubious numbers.
It bears repeating: do not blindly trust derivative drawings! Even the drawings in LOCs can be a bit odd. Witness the Martini-Hanry case drawings!
Patrick
Try drinking some coffee, use some eye drops and try using a LARGE magnifying glass.
(what are the chances of two people drinking CNC cutting fluid at the same time in the same Enfield forum)
Gentlemen, SAAMI = .4601, British drawing = .460
(I wonder if they are both putting grease or oil on their glasses and are suffering from excess eye thrust) :rolleyes:
http://i122.photobucket.com/albums/o...51/blind-1.jpg
Hmmm 2.54 microns Ed, OK, maybe I'll let it go!
Patrick
Mr. jmoore and Patrick Chadwick
The only reason I corrected both of you on the base diameter is because I got it wrong once myself when reading this very same SAAMI drawing and Parashooter corrected me about it. To make up for my shame and guilt I corrected both of you.
(but I got two for one) :cheers: :D
If you will carefully look at Parashooter's original posting you will notice there is a small triangle "flag" by the .4601 head diameter. Then check the notes at the bottom of the drawing. The flag note indicated by the triangle says that the .4601 is a reference dimension. That means the dimension is derived from other toleranced and some times basic (untoleranced) dimensions on the drawing.
IOTW discussion of the .0001 difference is a time waster.
The .4601 is provided for reference only and is not an inspected dimension.
:lol: Doesn't take much to set y'all off, now does it?:rolleyes: