The still left cartridge's headstamp states "FC 223 REM" which implies that it was produced by Federal Cartridge Co. and it's in the caliber .223 Remington. The cartridge on the proper provides a Two digits are the final two digits of the yr of manufacture. The _ga cookie, installed by https://remingtonprimers23567.blogpixi.com/20239987/5-essential-elements-for-5-56-primers