The M1917 Enfield is an American modification and production of the .303-inch (7.7 mm) Pattern 1914 Enfield (P14) rifle. Developed during 1917-1918, it was the main rifle used by the American Expeditionary Forces in Europe during World War I. As the UK entered World War I, it needed more manufacturers for the newly developed Pattern 1913 Enfield. Thus the U.S were given contracts to make them and while the UK had made them chambered in .276 Enfield cartridge, the rifles made in the U.S were chambered in the old .303 for convenience of ammunition logistics. Winchester and Remington were selected to manufacture these new rifles including a subsidiary of Remington, Eddystone Arsenal. Thus, three variations of the rifle exist, labeled “Winchester,” “Remington” or “Eddystone”.