The Winchester Model 1907 is a blowback-operated, semi-automatic rifle produced by the Winchester Repeating Arms Company beginning in 1906 with production ending in 1958. It was fed from a 5 or 10-round capacity, detachable box magazine located immediately forward of the trigger guard. The only cartridge offered by Winchester as a factory chambering in the Model 1907 was the .351SL centerfire. The energy of this cartridge approximates the modern .357 Magnum when fired from a rifle.