SMLE materials specifications

[Bruce_in_Oz]

During the, somewhat undignified at times, discussion about the strength of L E actions, someone asked about the materials used in manufacture.

Well, which bit do you want to know about?

I have in front of me a document called:

Specification No S.A./462 P, being for Rifle's No1 Mklll, with bantam long, normal and short butt (S.M.L.E., .303-in. With cut-off.)

Refers to 57/Spefns/3866 Approved 14. 12. 1938

Received by somebody careless on 19 JUN 1939

And it says:

Body -- Steel. B.S.S.5005/401 -- Partially oil hardened, tempered and browned.

Barrel -- Steel. D.D.8 -- (Heat treated)

Bolt, Breech -- Steel. D.D.8 -- Oil-hardened, tempered, polished and browned or oil-blacked.

Head, breech bolt -- Steel B.S.S.5005/103 -- Case hardened and polished

Further, on page 8 it states: "If the bolt-head be made of mild steel it is to be marked with the letter "M" on the top of the wing."

NOTE: earlier specifications (S.A./242 for Rifle, Short, Magazine, Lee-Enfield (Mark 1). |C.|) 13th July 1903, called for the bolt-head to be made from malleable cast-iron, specifically 34F Special gun iron, case hardened.

Regarding barrel proof, refer to page 12:
(g) Proof. - The barrel will be submitted with the action attached for proof. The distance from end of bolt to face of barrel will be tested with a cartridge head gauge .067-inch. The proof will then be carried out with a proof cartridge, the charge being about 33 grains of No.3 cordite, having a service bullet of 215 grains, giving a mean pressure not below 24 tons per square inch, after which the action will be examined; and the barrel, body, and bolt head will be marked with the proof mark."

I have started doing a scan and OCR on these documents. The originals are wax-stencil prints on foolscap size paper. The long tables are probably going to give me the horrors. Happy to bung them into the "library" on completion.

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