Nose Cap Fitting Question

[230Ball]

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!

Information

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[tbonesmith]

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.

[Bruce_in_Oz]

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.

[Peter Laidler]

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

[230Ball]

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?

[Brian Dick]

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.

[Bruce_in_Oz]

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.

[tbonesmith]

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.

[230Ball]

Whew, that's a relief! 'Thought I may have to abandon my project on making my SMLE a tack-driver.

[Son]

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"