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The 223 ammo cartridge was first developed in the 1960s by Remington Arms Company, from where this cartridge got its name; 223 Remington. The cartridge was designed at the request of the United States Continental Army Command (CONARC) as they were seeking a new powerful and small-calibre high-velocity weapon system. Since the army required their soldiers to carry as much ammunition as possible so they would not run out during battles. 

6.5 grendel ammo