7.62 Enfield question for Mr. Laidler

[jmoore]

I asked this heat treating question for a very good reason, I wanted to find out how many forum members here find it entertaining and fascinating to read or gather boring technical facts in obscure manuals that has nothing to do with collecting Enfield Rifles.

I LOVE reading boring technical facts- I made a four year degree into eight by poking my nose into obscure manuals and books (which, unfortunately weren't related to actual course work!). Well, that and working in the firearms trade to pay for school and...

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[Alfred]

I LOVE reading boring technical facts- I made a four year degree into eight by poking my nose into obscure manuals and books (which, unfortunately weren't related to actual course work!). Well, that and working in the firearms trade to pay for school and...

The technical details are what I'm most interested in.

The bolt heads used for the 7.62 conversions seem to have been purpose made , and should benefit from the more advanced metalurgy available at the time.
Some older rifles may not have had the best metalurgy, though no doubt the best available at the time, while those rifles constructed in India between 1950 and 1965 are known to have used a alloy that did not stand up well to the oiled proof rounds, the alloy being replaced in later production.

Also since much of the available milsurp .303 and 7.62 ammo may not have been stored under optimum conditions the details of damage to rifles from heat damaged propellants should be of interest to modern day shooters.
Its not uncommon to see collectors telling of shooting .303 ammo manufactured as early as the 1920's, so besides the more common problems associated with old ammo theres the fact that ammo that old did not benefit from advances in production techniques of later years.
Ammo produced in the 1920's for example is associated with the Stress Corrosion Cracking of case necks and other problems, though this seems to have been confined to India, a result of ammonia vapors in the air during the monsoon season. There same effect was noted with ammo stored in stables along with cavalry gear.

I've run across 7.62 Nato ammo so degraded it was scary. Pinholes and cracks in cases and gilding metal flaking away from the steel jacket.
When the powder was put in a steel powder can it dissolved the can into a pile of red dust, and vapors rusted and deeply pitted every steel object near it though these had been well oiled.


According to literature of the pre WW1 period charges of ammo intended for use in India and Africa were reduced, due to excessive pressures when ammo was stored for long periods in hot climates. These days the temperatures here in the Southern US can rival those of early 20th Century Africa. Temperatures in a car trunk can reach 180 degrees after a few hours in the sun even on mild days, and about that high in the passenger compartment if the windows are rolled up.
RAF tests on ammo cases in the Indian Northwestern Fronteir revealed that they could reach temperatures of 160 degrees if exposed to direct sunlight.

Theres just no way of knowing what abuse ammo has been subjected to before being declared surplus. If it was still good ammo they'd use it up in training, or in the case of Canada they'd issue it to the Rangers.


Besides the safety aspects, you'll find that details of manufacture are of great interest to collectors of everything from Hummel Figurines to Singer Sewing Machines.