303 ammo

[Bruce_in_Oz]

Roger:

The Germans were among the first to go away from mercuric primers way back in the early 20th. Century. I recall that the Swiss and the Swedes were keen on the same thing. If the primer cups are "copper" it is almost certainly Mercuric primed, as the mercury does evil things to brass, as every potential and actual reloader of once-fired military .303 brass that originated in Britain, Australia, India, etc will attest.

All primers had the chlorate component to extend the "brissance" of the initial "flash" from the mercuric or lead-based "initiator". It is the "chlorate" reducing to "chloride" during that process that causes the problem.

Early "non-corrosive" priming brews were tried in many sporting cartridges, but military uptake was slow. This seemed to be partly because of the old, "if it ain't broke, don't fix it" mindset; in a military situation, the Sergeants would be supervising weapons cleaning and especially that carried out before returns to the armoury. Civilian users? Not quite the same degree of "adult supervision".

Secondly, early "con-corrosive" brews were found to be "unreliable" in extreme heat or cold and it took a fair while to do "aging" tests to see what happened in long-term storage, even under ideal conditions.

Somewhere around here I have a bit of data on the various service primer recipes: To the Bat-Cave! There is no way anyone should be contemplating "rolling their own" primer mixtures and "re-filling" primers unless their insurance is VERY comprehensive.

There were several attempts to introduce "non-corrosive" primers to various military systems, but until it could be ascertained that it was worth the effort, not much changed.

Universal fielding of gas-operated rifles and machine guns post WW2, saw rapid adoption of not just non-corrosive ammo, but the parallel rise in the extensive use of hard-chromimg of barrels, gas pistons and cylinders, and so on. The hard-chroming was not just to ward off corrosion, but to reduce wear and particularly, erosion in barrels. Stainless steels are useless in machine-gun barrels because they erode even faster than Moly steel at the high temperatures that develop, especially during "sustained" fire. The "Green Machine'" can be fairly profligate with replacement of "critical" parts like barrels when the need arises. Those of us without such lush, tax-payer-funded budgets need to be a little more circumspect and resist the urge to send next month's family food budget down-range whilst burning out an irreplaceable barrel.

And even when shooting within sane budgets, "cleanliness is next to ..... " and all that jazz.