chauchat
A French light machine gun (or automatic rifle) of World War I. Notable for its half-moon design 20 round magazine, which was the main source for the weapon's abysmal combat record - it jammed often, feed issues were common, and attempting to load a full magazine into the Chauchat would almost inevitably cause it to fail to chamber the first shot, which is why it was usually only loaded with 16 or 18 rounds in the mag.