Buffalo Bore loads their ammunition up to maximum SAAMI specifications, which delivers devastating performance on a wide range of game. Please note that this ammunition is not intended for older guns. It is made for modern firearms only, as some of the ammunition could damage older and weaker firearms. This heavy 38-55 ammunition is for use in any firearm chambered in 38-55 or 375 Winchester that is in normal working condition and designed to be used with smokeless powder. This ammunition is new production, non-corrosive, in boxer primed, reloadable brass cases.