The PPSh-41 drum magazine was a copy of the Finnish M31 Suomi magazine. It held 71 rounds. The drum magazine was slower and more difficult to load with ammunition than the box magazine. The box magazine began to be used more after 1942. Even though it had less bullets in it, the box magazine made it easier to hold the weapon. It was possible that the PPSh-41 would fire bullets if it was dropped on a hard surface. This was because of its open bolt design.