Lee Enfield chamber reaming in the Great war?

[Homer]

Look you blokes just leave that forum alone! Even though I'm not aloud to post there anymore, I still get a great deal of entertainment from it!

[Bruce_in_Oz]

That table is lifted from the "EMEI" WPN D117, Issue 1, Sep '76.

Note that date!!

This document is part of the "workshop" paperwork for the SMLE sniper rifles STILL in service in the mid 1970s.

The "HT" rifles were eventually replaced by the Parker-Hale M-82, starting in late 1978. The P-H M-82 units were then replaced by the Accuracy International in 1999.

[mike1967]

You forgot the traditional Formica.

Mind boggling.................... Credit card and coke cans...........

[Brian Dick]

I had a couple of boxes of ten each, new old stock SMLE "long" bolt heads that all measured .640. They were British manufacture and coded M621 so I'm guessing WWII replacements. I still had to select fit for over/under turn and stone down the faces to bring into MoD spec when fitting them to remedy headspace issues. Many were used on RFI 2A and 2A1 rifles which were almost always out of spec. I've never seen numbered SMLE bolt heads either. If I had $10 for every phone call from a confused LE owner who's been reading that sort of crap on the internet, I'd be a very rich man. That's why this is the ONLY forum I even bother to frequent.

[Bruce_in_Oz]

It is worth pointing out that striker protrusion is set by the relationship between the TOTAL length of the bolt head and the distance from the tip to the "collar" on the striker.

ALL SMLE components are made from various grades of "Carbon" steel. ""Alloy" steels could ONLY be used by a maker upon approval of samples of the material submitted to the demi-gods at Ordnance / War Dept.

The taper on the striker forward of the collar is a fairly close match to the interior of the bolt head.

The trick is to select and fit a bolt head to a bolt body before fooling around with other parts.

If the new bolthead achieves headspace within tolerances, fine.

Do not try fitting a new bolthead with the bolt body "internals" in place ; it's a a bit tricky to "adjust" the bolt body with the striker in the way. Furthermore, leave the extractor off the bolthead whilst fitting; you get a greater degree of "feel" as the bolthead closes on the headspace gauge; no pressure from the extractor sliding up its little ramp.

BEFORE you go to the drama of re-fitting the striker, spring and cocking piece, check the striker protrusion by inserting it into the bolthead and gauging it.

If the striker spring looks shabby (pitted) and/or is below length, replace it; there must still be millions of these things out there; most users baulk at the prospect of changing them. The EXACT same spring is used in the SMLE AND the No4.

The spring specs are:

OAL: 3.3" -3.375"
OD .363"
ID .252"
32 coils of No. 18 SWG
Ends ground to length. NOT CLOSED

Strip ONCE, Assemble ONCE. This is especially important regarding the fit of the cocking piece to the striker. There is a 0.001" tolerance on the diameter dimension of the respective bearing surfaces on the striker and inside the cocking piece. It is effectively an interference fit of those parallel surfaces if assembled correctly.

[Son]

Never seen that chart, thanks for sharing.

Mike, as much of the document as I have is posted at the bottom of the MKL entry on the HT rifles here...
Milsurps Knowledge Library - 1917/1945 No.1 MkIII* H.T. Sniper Rifle (Short Bracket)

[Son]

Further from before....

I found that the myth of oversize and out of round chambers came from an early reaction to handloading commercial brass.

We can all accept that the chamber in the Lee Enfield Rifle was designed to be "generous" in comparison to the ammunition specs no matter if you feel it was to allow for so many different makers of ammo around the world or the ability of the rifle to continue to cycle flawlessly in the most adverse of battlefield conditions. This trait is what lead to it becoming known as the most reliable battle rifle ever.

(Apologies for going back to basics here, but you will see where it takes us...)
The design of the cartridge being rimmed allowed it to be headspaced at the rim and that meant there was no need for any other tight tolerances in the chamber.
A rimless cartridge is dependent on the shoulder seating on a corresponding part at the front of the chamber, so the critical measurement area is the whole length of the cartridge/ chamber. There is no room for "battlefield debris". This characteristic meant that handloading rimless cases did not involve a great deal of case manipulation.
Here is a pic of an unfired .303 case and a fired case. If a rimless cartridge was fired with this much space in front of the shoulder probably would not have gone off... the striker would have pushed if forward into the chamber and then not marked the primer deep enough.
Attachment 69538

The eventual drying up of surplus ammunition meant that shooters had to reload to keep going. When you stick a commercial cartridge into a LE chamber, a few things happen... Firstly, they are most often thinner in the rim and usually smaller diameter at the base of the case. They most likely had shorter projectiles in them and so the round would sit at the bottom of the chamber... nothing to locate it centrally.
On firing, the striker would stake the primer where it sits and then the case expands out to the chamber. Because the primer is impaled on the striker with the case sitting at the bottom of the chamber, the top of the case would expand out to the chamber and the bottom could not.
Looking at the primer strikes you will see the majority are well off center. Some with softer primer cups will actually show an extruded side to the strike where the expanding case has moved up ward in the chamber and made a lip on the primer strike indent which will be toward the centre of the base.
Attachment 69539

Bottom line is, the need to use inferior made undersized commercial cases left the handloader with a distorted once fired case that he could not explain the shape of. Naturally people like the ones on the flat earth forum have done nothing to help the situation making up all sorts of crap to make themselves look like the x-spurts....

The simple truth is these rifles were never made to re use the brass. They did what they were made for very well, but if you need to apply modern reloading techniques to keep using your rifle, then there are a few tricks you can apply to maximise case life. When it all boils down, all the kafuffle came about over case life anyway.