<P> The M1911 is a single - action, semi-automatic, magazine - fed, recoil - operated pistol chambered for the . 45 ACP cartridge . It served as the standard - issue sidearm for the United States Armed Forces from 1911 to 1986 . It was widely used in World War I, World War II, the Korean War, and the Vietnam War . The pistol's formal designation as of 1940 was Automatic Pistol, Caliber . 45, M1911 for the original model of 1911 or Automatic Pistol, Caliber . 45, M1911A1 for the M1911A1, adopted in 1924 . The designation changed to Pistol, Caliber . 45, Automatic, M1911A1 in the Vietnam War era . </P> <P> The U.S. procured around 2.7 million M1911 and M1911A1 pistols in military contracts during its service life . The M1911 was replaced by the 9mm Beretta M9 pistol as the standard U.S. sidearm in October 1986, but due to its popularity among users, it has not been completely phased out . Modernized derivative variants of the M1911 are still in use by some units of the U.S. Army Special Forces and the U.S. Navy . </P> <P> Designed by John Browning, the M1911 is the best - known of his designs to use the short recoil principle in its basic design . The pistol was widely copied, and this operating system rose to become the preeminent type of the 20th century and of nearly all modern centerfire pistols . It is popular with civilian shooters in competitive events such as USPSA, IDPA, International Practical Shooting Confederation, and Bullseye shooting . Compact variants are popular civilian concealed carry weapons in the U.S. because of the design's relatively slim width and stopping power of the . 45 ACP cartridge . </P> <P> The M1911 pistol originated in the late 1890s as the result of a search for a suitable self - loading (or semi-automatic) pistol to replace the variety of revolvers then in service . The United States was adopting new firearms at a phenomenal rate; several new pistols and two all - new service rifles (the M1892 / 96 / 98 Krag and M1895 Navy Lee), as well as a series of revolvers by Colt and Smith & Wesson for the Army and Navy, were adopted just in that decade . The next decade would see a similar pace, including the adoption of several more revolvers and an intensive search for a self - loading pistol that would culminate in official adoption of the M1911 after the turn of the decade . </P>

Who made the first 1911 semi automatic pistol