Threads front main screw No1 mk3 and no3/pattern1914

[ssj]

Just to double check something, the front main screw thread pitch, diameter and angle on both the above is the same? I have a snipers sling point and the threads are finer than my no4 and seem to match the pattern1914 original main screw OK. Seems I bis on 3 x no4 ones when actually I have 3 of something else, either no1 mk3 or pattern1914 (is there a difference? one is longer than the other 2. Either that or the front screws are not right and bubba has caught me.

Information

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[Bruce_in_Oz]

The threads in No1 (SMLE) series and the P-14 are pretty much ALL “Enfield Specials”. Not only are the pitches “creative”, the form (angle) is unique. It must have kept the American contractors amused for weeks getting their heads around them, especially as the Americans themselves, were still getting used to their own, relatively new, “Unified” thread system.

After the ”First Great Unpleasantness”, it seems that someone had the bright idea that, the “new” rifle should have threads that were in common use in British and Commonwealth industry; eg., Whitworth and BA. This was prompted by the shambles that ensued when industrial-scale war had demanded incredibly rapid expansion of rifle production and the consequent mass use of sub-contractors to provide all the “fiddly bits”; ( the "Peddled Scheme").

The old “Enfield Apprentices” website actually used to have a list of all the thread used in Enfield-designed / built small arms.

Regarding the Front Triggerguard Screw: The diameters are nominally the same; 0.250”. HOWEVER, the threads are utterly different in pitch AND form. The SMLE (and its predecessors) used a ¼” x 30 TPI, Enfield Form, (a bit like BA, but with a 49 (ish) degree included form angle), whereas the No4 and 5 (and derivatives), went with "industry standard", ¼” x 26 BSF (55deg).

[Mk VII]

In WW2 Mossberg had great difficulty persuading anyone to make thread gauges for the sub-contracted L-E parts they were making for Savage-Stevens. They ended up making them themselves.

[ssj]

Thanks, I checked the sling mount screw against the standard screw and it looked OK but I was assuming the standard screw was the right one!

[Peter Laidler]

Just as a litle aside SSJ, I'm sure I won't be the only one but sometimes can't identify the parts you mention. Such as main screw (thread 1) and sling mount screw (thread 4). Is this the screw for the butt/lower band sling swivel or the sling swivel on the what you call the 'main screw'. What we call the SCREW, front trigger guard?

As you can see, giving you an Enfield size, or 4BA size or 1/4 BSF over the forum could great problems or confusion here............