About 75% of all the brass I own is military "once fired". It is a one time deal to remove the crimp (all my brass was "de-crimped with a countersink) and actually really simple and fast. My ex-military brass is 9mm, 45 ACP, some 38 Specials, 7.62x51, 30-06, and IIRC, a few 7.62x39. I figger I'd have about 2,000 fewer cases if I didn't reuse mil surp...