First up, I know the 1873 isn't a pistol. But there are, were, is pistols chambered in 38-40 (I'm pretty sure anyway). My issue is the length needs to be right for the 1873 action to cycle the rounds. I formed some experimental cases from .303 brass which worked/chambered fine at correct length for a projectile, but i couldn't get a full brass full length case by just fireforming. Will sizeing the brass down first help, or is the shape of the chamber less than ideal for this project. Im new to this game and I live in Australia, so getting custom cases from the states is so difficult and expensive so as to be damn near impossible.