The Fusil Automatique Modèle 1917 (often called the RSC M1917) was a French semi-automatic service rifle introduced during World War I to increase infantry firepower. Developed by engineers Paul Ribeyrolles, Charles Sutter, and Louis Chauchat, it was designed to give standard infantry units a faster rate of fire than the bolt-action Lebel Model 1886 rifle then in service. The rifle used a gas-operated mechanism and was chambered for the 8×50mmR Lebel cartridge, feeding from a five-round en-bloc clip inserted into a magazine beneath the receiver. Introduced in 1917, it became one of the first semi-automatic rifles issued in meaningful numbers to regular troops rather than being limited to experimental or specialist use. Although it improved the soldier’s rate of fire, the rifle had drawbacks such as sensitivity to dirt and a somewhat complex mechanism adapted to the rimmed Lebel cartridge. Despite these issues, the M1917 represented an important step in the evolution of infantry rifles and influenced later French semi-automatic designs.