Dating cartridge headstamps
Worldwide, there are over 800 military headstamps in existence plus some 400 or more commercial headstamps that have existed at various times.
Obviously, this is a complex and highly specialized field.
Plant 21, Uzinale Metalugica Di Copsa Mica Si Cugir, Romania.
Normally found on cartridge headstamps followed by the letters RPR which stand for Republica Popolara Romana (People's Republic of Romania)Originally A-ZOOM Ammo, A division of Ready Products Corp., 4 Chrysler, Irvine CA 92618 (800-61READY).
Cartridges intended for sporting or civilian use usually have two elements; one identifies the specific chambering, the other identifies the manufacturer.
Rimfire, AL EP, G or G, HP, F, XL, XR and WM Centerfire, FC General Electric Co. NA plus caliber (Made by Rem.) Peters Cartridge Co. U, UMC, REM, REM*, UMC, R-P, RAH Robin Hood Ammunition Co.