No.4 trigger stoning..and other question

[Bruce_in_Oz]

But WAIT!!! There's more!!

I finally found my copy of the 1903 specification for the Rifle, Short, Magazine, Lee-Enfield (Mark 1) dated 13th. July, 1903. This is what happens when you shuffle furniture around whilst renovating / painting your house!

Anyway, the 1903 Spec. lists:

Body: 56 A 71 - MILD STEEL (Partially oil hardened, tempered and browned (blued))

The "recipe" for this stuff is:

Carbon - 0.5% to 0.6%
Silicon - From 0.1% to 0.3%
Manganese - From 0.45% to 0.50%
Sulphur - NOT ABOVE 0.04% (NB Sulphur seriously degrades "barrel" steel. It is EXTREMELY deleterious in stainless steel barrels, as some individuals and makers have found to their cost and horror)
Phosphorus - NOT ABOVE 0.04%

Barrel: 110 A - Crucible or Siemens-Martin Steel (Browned) NB. This is a GERMAN special steel: I'll bet things got interesting come 1914!

Bolt: 56 A 42 - Crucible Cast Steel (Oil hardened, tempered and browned)

Bolt Head: 34F Special Gun Iron (Case Hardened) The notes only say:

"The iron must be clean and free from seams and small :greys", as the slightest imperfection shows itself when the material is polished and case-hardened. The ultimate tensile strength per square inch must not be less than 22 tons, with a minimum elongation of 15 percent and a minimum contraction of area at point of fracture of 45 per cent. In a further twist, this same material is used for the two Butt-plate screws.

Cocking Piece: 56 A 42 Cast steel (Hardened, tempered and oil blackened)

Sear: 56 A 43 BEST Cast Steel (Hardened and tempered))