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Currently following a couple of established practices on maintaining barrel float on a No. 1 Mk III*, to include muzzle clearance at the nose cap. The muzzle on my SMLE makes contact with the nose cap for the full circumference. Has anybody removed metal to achieve muzzle clearance in the nose cap, and if so, what method to ensure symmetry? I realize only .005" is needed; however, I'm looking for the proper technique to avoid any semblance of Bubbafication.
Thanks in advance!
I think that, that form of bedding would amount to "Bubbafication" regardless. But I would be thinking of some lathe mounted fixture and boring the hole out, or the same on the mill. I am pretty sure that most of the ones I have seen have been done by running a drill bit through the hole then filing it. And the clearance on the ones I've seen have been more like 0.050+" all round than 0.005". And this is not in any way a recommendation, just an observation.
Just back away slowly from the tool box!
SMLEs, or at least No1 Mk3 variants, have a fairly complex bedding set up. This was done in order to "compensate" for the sundry "waves and vibrrations' generated by the use of Mk7 ball ammo.
EARLY (Mk1) SMLEs are NOT set up the same way as the more common Mk111* types. They were "regulated for" the older-styled round-nosed ball ammo for a start.
The advent of the "high-velocity" Mk7 threw all that out the window. Not only did the sights have to be re-designed, new magazines were required to correctly handle the new "pointy" ammo.
But wait! There's more!
Mk 7 ammo generated a completely different set of wave patterns in the barrel.
DO NOT open out the muzzle hole in the nosecap.
Have a close look at it; if "un-butchered", the hole SHOULD be a close, but not tight fit around the barrel. HOWEVER, there should be a small "extra" cut out at the top of the hole. This is to provide two tiny "points", about 5mm apart. It is on these two points that the barrel is actually "bedded".
The coil spring and plunger that SHOULD be fitted near the rear of the nosecap is there to push the barrel upwards onto those points in the barrel hole in the nosecap.
Then, further back, there SHOULD be a band around the barrel. This band should have a screw and spring pulling it DOWNWARDS, but NOT holding it tight against the barrel channel in the fore-end channel.
All of the rest of the bedding back towards the receiver body is designed to hold the wood and steel in the correct alignment so that the forward "gizmos" apply the correct pressures to the barrel.
HOWEVER, ALL of this creativity was designed, after a LOT of experimentation, to provide consistent GROUPING with Mk 7 BALL ammo and NOTHING else. Once consistent grouping is achieved, zeroing the sights is pretty much a walk in the park.
Use of any ammo other than Mk7 will produce different grouping and MPI results from what was originally desired. Trajectory tables will also go out the window.
However, if you are only shooting at a few hundred yards, once you have a reasonable group, just make your adjustments and live with it.
The only way to be able to use the sights as calibrated, all the way out to seven or eight hundred yards, is to use good, old corrosive and erosive Mk 7 ammo. Good luck with finding a decent stash of that!
If you are only banging away at two or thee hundred yards, you can "fake it" with whatever you can load or buy.
"Proper" Mk 7 bullets loaded over a correct charge of a propellant with similar burn characteristics (minus the extreme high temperature) to Cordite would be a good start.
There should be a tick box to leave DOUBLE thanks. That's what the good, sound advice you've both given there really deserves TBone and BinO
Many thanks gentlemen for the sanity check and sparing a piece of history! I'll take her to the range "as is" once it gets a little warmer and let you know.
BTW, I have a few boxes of Prvi Partizan 174g FMJ. How does that compare to the Mk7 issue ball ammo?
PPU doesn't compare because it's more or less Mk.8 with the boat tail bullet. Many SMLE and No.4 rifles that have seen a steady diet of cordite Mk.7 during their careers won't stabilize the boat tail bullet because of wear patterns in the leade or throat of the barrel. I've seen them keyhole at 100 yards because of this problem. It's all been discussed on this forum extensively in the past.
The odd thing is that the nice folk at Privi Partizan seem to actually make, or at least advertise, Mk7 ball ammo. (Or at least they did in the recent past).
For some odd reason, nobody seems to import it into countries infested with rifles that should be using it.
Not withstanding Brian's accurate comment, plenty of rifles handle the PPU ammunition with no issues at all. It costs nothing to give it a run.
Whew, that's a relief! 'Thought I may have to abandon my project on making my SMLE a tack-driver.
If I may, can I re visit the MkIII bedding. There are a couple of points of contention here. Where I totally agree with Bruce in Oz about what an armourer might find or work to achieve when working on a rifle which has been in service, this wasn't quite how they were to be set up from the factory.
From the factory, the foreend fit was achieved without any of the metal parts.
From "The Armourers Handbook Part 1 The Rifle"
Barrel Bearings
1. There must be hard bearing at the draw, which transmits the shock to the stock.
2. A distance of 1 inch back from the front end of the body.
3. The reinforce or bearing of the barrel
4. The inner band, half inch either side
5. There should be light bearing from the inner band to the top when fitting.
The LoC says in regard to the introduction of the inner band...
Band, Inner- The inner band which encircles the barrel at the centre with .002-inch freedom, is fitted inside the foreend, and is held in position by a screw, spiral spring, and washer, so that it supports the barrel, without holding it rigidly, or preventing expansion
From the 1942 Textbook as quoted in the LES from P160 on fitting a new foreend...
(d) ......... examine the barrel groove for seating of the barrel at the reinforce and for a distance of 1/2- inch above and below the inner band.
Page 123 LES, notes on introduction of the Short, Magazine Lee Enfield Rifles, Marks III and IV (which compares differences between these rifles and the MkI rifles)
The barrel is supported by the foreend except from about 1/2-inch from the rear of the inner band recess to the knox form[/I]
And about the MkI " The foreend is freed from the barrel throughout except from about 1/2-inch in front and 1/2-inch behind the inner band recess and under the knox form."
From the notes regarding introduction of the SMLE MkI, regarding the nosecap, P 108 LES
... the muzzle of the barrel has .002" freedom in the barrel hole.
The "Stud, and Spring" in the nosecap were not part of the original manufacture of the SMLE MkI. They do not appear in the list of component parts for either of the introduction announcements for the SMLE MkI, but there is an alteration LoC 13509 where the stud and spring were introduced, two listing dates, 10 April 1905 and 24 Oct 1905. The entry reads...
The stock, foreend has been recessd to receive a stud and spring to centre the barrel in the nosecap..... Foreends fitted with the new stud and spring are marked with the letter "S" below the nosecap.
Interestingly, the parts list for the introduction of the SMLE MkIII rifle lists the stud and spring as being "common to all marks" meaning they were fitted to the MkI models.
In summing up all the information regarding barrel bedding, the inner band and the barrel centring stud, both the SMLE MkI and MkIII had the barrel bearing at the knox form, and either side of the inner band recess. The MkI floated from 1/2-inch forward of the inner band recess to the muzzle initially, but was then (post LoC 13509) supported by the barrel centring stud which lifted it to the nosecap hole. The MkIII barrel was bedded to the foreend from the inner band recess to the muzzle.
The inner band and the barrel centreing stud, although doing nothing in a correctly bedded MkIII barreled action, were retained to reduce the ill effects on accuracy of warping to the foreend. Accuracy problems were identified early in the SMLE MkI useage causing the introduction of the stud as a bandaid. These problems were later alleviated by bedding the barrel to the foreend, all the way to the muzzle in the MkIII but the band and stud were kept for the same reason. As warping took the foreend pressure from under the barrel, the stud and spring came into play, as did the inner band if the foreend came away mid barrel too. The nosecap did not contact the barrel unless the foreend bedding had changed and the cetreing stud has come into play.
hope this all makes some sense... still chasing further refences....
Inserting a pic of a Lithgow foreend that was unissued and unfired from proof and testing when I got it. Note the marks at the knox form and from before the inner band recess all the way to the muzzle showing barrel contact.
Attachment 48567
As an aside, experimentation done in the fifties (IIRC) confirmed that the position of the inner band on the SMLE barrel was not in a position where it would dampen vibration from MkVII ball. There are pages of notes on nodal point experiments in James Sweet's "Competitive Rifle Shooting"
Interesting photo!
Let me toss these thoughts out there:
It would seem to make sense that the inner band should be at a "natural" NODE.
Thus, the barrel forward of this node would be "free" to vibrate. Having the muzzle tightly constrained by the front of the nosecap would affect the frequency and amplitude of this vibration. What was needed was consistency. Hence, upward pressure from the plunger and the two bearing points in the nosecap, as provided by the additional cutout
A "free-floated" barrel does not just vibrate in the vertical plane. The barrel also STRETCHES, BULGES and TWISTS, albeit to a fairly small degree. Thus the trick was to constrain the modes in which the barrel could vibrate in such a way that any vibration produced consistent results. It didn't matter too much where the muzzle was pointed at the time of bullet departure, a slong as it was more-or-less the same from shot to shot. Without some degree of consistency, grouping would be "interesting" and sight adjustments a complete lottery. As it was, the front sight base on a SMLE has a built-in lateral offset of fifteen thou. before you start fiddling with the blade. The "ears" on the nosecap are similarly offset. This offset is a "gross" compensation for the performance of the rifle/bullet combination in the real world.
Wood has an annoying propensity to take interesting "excursions" as moisture content changes, hence the "system" took considerable pains to get the finished woodwork as stable as possible.
Firstly the wood used for the basic "flitches" that were fed into the profilers, routers etc., was subject to painstaking selection and seasoning, often for many years.
Secondly, it would seem obvious that the rifle had to be tuned to strictly standardised ammo, not the other way around as in "sporting" practice. One million mass produced rifles had to perfrom to spec with ammo produced by the billions.
This doesn't just apply to Lee Enfields. The Swiss went through the same drama with their 1911 model rifles and carbines, introduced the same year that the fabulous GP-11 cartridge arrived. Thus, the "new" Swiss rifles had to work with both "old" and "new" ammo, for decades, perhaps. Like SMLEs for many years, they were "long" throated to accept the older ammo. Interestingly, the K-31 has a short throat (well, at least the ones I have examiined) that is exclusively for GP-11 ammo with its secant-ogive bullet.
Another interesting thing about the Swiss K-11 is that it has a small, adjustable collar around the barrel, inside the fore-end, right near the front. This is apperently both a "bearing" and a a "tuning" device. It appears to be made from "Nickel-Silver" or similar material.
In related trivia, when the Swedes introduced the AG-42 / (B) gas-operated rifle in the early '40s, the rear sight had a reversible range drum: one scale for the old round-nosed bullet and one for "spitzer" projectiles. The two different bullt shapes are clearly marked on the drim assembly. The barrels were throated to accept ALL types of service ammo.
Just a couple of points, all pretty well non contentious. Early lesson during basic projectile properties was that the projectile doesn't care a fart about what's happed where it's BEEN. It's only concern is where it's going to pass because that is what is going to affect it. I wish I'd learned the exact phraseology as it made so much more sense. The next bit was that the barrel is nothing more (?) than a simple tuning fork. Not sure that I'd necessarily agree with that because it is a tad more complicated but that's how I learned it for exams! And how true BinO is when he repeats again and again the fact that the barrel don't only vibrate in one plane.......... It's vibrating in ALL planes and this is further complicated by the fact that while all the wood ain't the same, nor are the steel properties.
The only people who would REALLY and truly understand the greater technicalities of a barrel are music graduates because it's really all about vibration and harmonics. And while we're on about really truly great harmonics, sad day for the loss of Phil Everly. Want to hear some great harmonics, listen to a little known/played number. So Sad by Don and Phil Everly
Maybe the couple of points I was trying to make were swallowed up and went unnoticed. Bruce in Oz's statement about the inner band and the barrel and the barrels relationship to the foreend at that point was incorect.
"Then, further back, there SHOULD be a band around the barrel. This band should have a screw and spring pulling it DOWNWARDS, but NOT holding it tight against the barrel channel in the fore-end channel".
My main aim was to point out respectfully, with documentation, the barrel is supposed to have heavy bearing on the foreend either side of the inner band recess and the band does not have to make contact on a correctly bedded barrel. I understand there are complexities in the harmonics, but as Bruce said so well, the whole purpose isn't to stop the vibrations, but to ensure their effect is exactly repeated at every firing. The vast majority of accuracy attaining rifles these days have heavy fluted barrels, fully floating. Speaks volumes for the experiences of weapon designers over the last century trying so many weird and wonderful ways to make them shoot.
As for the "interesting pic", I would expect to find similar marks in the vast majority of SMLE foreends. Here's three that were easy to hand for a pic. Two from the forties and one WW1 vintage
Attachment 48587
Thanks BruceIO and Son for a very interesting discussion. Over the last couple of days (with the temp hovering around minus 20-25C) I've been doing some aimless interweb searches and stumbled upon an individuals efforts to build a finite element model of a bolt action rifle (generic). For this particular model he reaches the conclusion that: "recoil and forced deformations are much more important than the natural vibration modes in determining where the barrel is pointing when the bullet exits the muzzle". In other words the barrel (and entire rifle) undergoe deformation during the firing not entirely related to how it vibrates post bullet leaving the muzzle. Anyone ever see an attempt to model the SMLE in this way? It would be interesting as our favorite gun does have some unique characteristics. The website, incidentally, is "varmintAl.com".
I gather the key barrel support points are (from the muzzle), nose cap (where it contacts the muzzle), forend stud, inner band, and knox form. On my particular example there are voids in the wood surrounding the knox form. Should I add bedding compound to fully support the knox form, or am I overthinking this?
BTW, thanks for answering my newbie inquiries. I am awed by your expertise!:bow:
How does it shoot as it is?
Honestly T-Bone, she hasn't been to the range yet with me. I'm taking advantage of the cooler temperatures here to ensure the rifle's up to spec, given its age. Is it taking too much of chance putting a few rounds through it "as is"? Chamber and bore look great, as well as the rest of the wood-meets-metal part. The only thing I'm waiting on now is the no-go headspace gauge. (BTW, I've ordered the Okie disc-type gauge, vice the standard. Good or bad choice?)
I would definitely shoot it as is before trying to improve the bedding. With these rifles you can't improve on "correct". The problem with adjusting the bedding is that unless you are an expert you will invariably do more harm than good. I think that everyone will attest to the generalisation that original is always better. There are exceptions, but if your rifle is anything like original condition then you are best to ensure that accuracy is a complete disaster before trying to improve it.
No1's are notoriously difficult to get right, and while there are many who can quote the written specifications there are very, very few who can reliably replicate factory bedding.
My suggestion is shoot it first and if it shoots reasonably well leave it be. If it is a complete disaster have a further look at it.
Quote:
Originally Posted by Peter Laidler
Example: both my Enfield Nr.8s were tested by RWS in Fürth. Very, very carefully. Barrelled systems held in a lead clamp to exclude everything except unhindered barrel vibration. Although the serial numbers only differ by 805 (i.e. probably manufactured within a couple of weeks of each other), the ammo that produced the best results was different for each rifle. Not just a different batch, but a different type. RWS reckoned it was a result of tiny differences in the steel affecting the magnitude of the harmonics.
And the best result: all shots touching a 3mm circle at 50 meters.*
Having read this thread with great interest, I now hope that I will be able to get better performance from my MKV, which up to now has been a disappointment. My thanks to all contributors.Quote:
Originally Posted by Peter Laidler
But it all confirms my opinion that soaking stocks, attacking the wood with oven cleaner (= caustic soda or equivalent), putting them in the washing machine, drying in the sun etc is A BIG MISTAKE if you want to have an accurate rifle. A century or so of wood stabilization gone in minutes for the sake of prettying up the rifle!
*No B-S. I have posted the groups in the past.
But WAIT: There's more!!
From specification S.A. 462P (1938):
"37. Stock, fore-end, "B". - Will be viewed in the finished stage. It will be gauged for size and figure, position of nose-cap; also for barrel; body; plate, keeper, stock-bolt; guard and sight protector seating; and inner band and fore-end stud and spring recesses. It will then be examined to see that the barrel groove is free from the barrel seating under the reinforce to approximately .5-inch to the rear of the inner band recess, and that the barrel groove is cut in line with the barrel hole in nose-cap from the inner band recess. The quality and condition of the wood will also be examined. The fore-end must be soaked in linseed oil for half-an-hour"
"41. Rifle, assembled. - Will be examined for fitting of butt, fore end, nose-cap, band, hand-guards and bayonet, and to see that the numbers on the bolt, body, nose-cap, fore-end, barrel, and sight leaf coincide; also that all components are marked with the examiner's mark, and that the proof mark is on the barrel, body, bolt and bolt-head. The barrel must be free in the fore-end, as described in paragraph 37. It is essential that the barrel should bear lightly against the upper portion of the hole in the nose-cap. .............etc., etc."
The Spec for the Mk1 SMLE is a little different, as one would expect for a rifle built around Mk6 ammo.
"42. Stock, Fore-end: ....Blah, blah, etc.....It will then be examined to ensure that the barrel groove is freed throughout, excepting at the barrel seating under the knoxform (sic) and about .5 inch in rear and front of the inner band recess."
Nowhere can I see a reference to the bearing on the nose-cap, HOWEVER, I just dug out and de-greased the one specimen of a Mk1 type nose-cap that I own. It has the "secondary" cut at the top of the muzzle hole as per a Mk111*. Was it made that way, or subjected to "upgrade" during conversion to one of the "multiple star" upgraded models? The serial number was ground off the bayonet boss a LONG time ago by a "previous owner". It is marked with what appears to be a King's Crown over "01" and "E".
Given that:
1. The "Mk. 1" pattern was not even sealed until 1902.
2. It was then "reintroduced" with minor changes in September 1903, and
3. Queen Victoria died in January 1901....
What did it this nose-cap come off? One of the trials rifles?
Do any of the owners of specimens of the multitude of .22RF conversions have rifles with Mk 1 style nose-caps?
Now, if someone had a stash of "work books" from the assembly departments of factories, we would have a more comprehensive picture.
Cheers,
Bruce
Hmmm, para 37 says to me see that the barrel groove is free from the barrel seating under the reinforce to approximately .5-inch to the rear of the inner band recess, the barrel is free from.... the barrel seating under the reinforce to .5 inch before the inner band recess.... I would assume anywhere not mentioned would be seated to the barrel.... 41 adds the confirmation of the nosecap contact as Bruce described. First time I had seen it written.
Digging deep into the nuts and bolts of this stuff is fun... Wish I had the resources of others, but will add anything I find on the topic after some more digging
I have a trainer with the MkI style nosecap, will dig it out and check it over tomorrow
I also have some hand written notes from an armourer to look through too....
Regards,
Brad
Forster will custom make you a real military style .074 Field gauge if you ask them. I've learned not to trust the coin gauges. I've had too many people send rifles here that were supposedly checked with them and were quite different than what they thought once checked with a proper gauge. Just my 2 cents.