jonnyc, you're partially correct. Frankford Arsenal did put their corrosive primers in some ammo after 1952. I'd forgot about that. But TW ammo after mid '52 all had non-corrosive primers.
Beginning in 1953 all GI ammunition, with the exception of some lots of armor piercing and FA Match, would be noncorrosive. The last use of the corrosive FA Number 26 primer was in the FA Match of 1957.
Some of Winchester and Western Cartridge Company's .30-06 and .308 Win. match ammo had corrosive primers up through 1958. They were the most consistant primers they made back then.
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