The M1911 (Automatic Pistol, Caliber .45, M1911) was developed by John Browning in order to nullify juramentados, for the then Army issue M1892 six-shot revolver with its 148-grain .38 caliber rounds proved inadequate to the task if stopping the hard-charging, blade-wielding Moro warriors. A number of veteran U.S. Army soldiers retrieved their former issue Colt Single Action Army revolvers from their foot-lockers after discovering that their heavier .45 caliber 255-grain projectiles proved more efficacious in stopping the deadly charges. With that information as design parameters Browning developed the famed pistol and the .45 caliber 230-grain "Ball 1911" round.