M1911A1

The Colt M1911A1 is a single-action, semi-automatic, magazine-fed, recoil-operated pistol chambered for the powerful .45 ACP cartridge, which served as the standard-issue sidearm for the United States Armed Forces from 1911 to 1985. It was first used in later stages of the Philippine-American War, and was widely used in World War I, World War II, the Korean War, and the Vietnam War. The M1911 is still carried by some U.S. forces.

It was seen in Commando.

Description
Its 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 era. In total, the United States 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 the early 1990s, 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, the U.S. Navy and U.S. Marine Corps.

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, because of the design's relatively slim width and the power of the .45 ACP cartridge.

Browning's basic M1911 design has seen very little change throughout its production life. The basic principle of the pistol is recoil operation. As the expanding combustion gases force the bullet down the barrel, they give reverse momentum to the slide and barrel which are locked together during this portion of the firing cycle. After the bullet has left the barrel, the slide and barrel continue rearward a short distance.

At this point, a link pivots the rear of the barrel down, out of locking recesses in the slide, and the barrel is stopped by contact of the lower barrel lugs against the frame's vertical impact surface. As the slide continues rearward, a claw extractor pulls the spent casing from the firing chamber and an ejector strikes the rear of the case, pivoting it out and away from the pistol. The slide stops and is then propelled forward by a spring to strip a fresh cartridge from the magazine and feed it into the firing chamber. At the forward end of its travel, the slide locks into the barrel and is ready to fire again.

The military mandated a grip safety and a manual safety. A grip safety, sear disconnect, slide stop, half cock position, and manual safety (located on the left rear of the frame) are on all standard M1911A1s. Several companies have developed a firing pin block safety. Colt's 80 series uses a trigger operated one and several other manufacturers, including Kimber and Smith & Wesson, use a Swartz firing-pin safety, which is operated by the grip safety. Language cautioning against placing the index finger along the side of the gun to assist in aiming was included in the initial M1911 manual, and later manuals up to the 1940s.

The same basic design has been offered commercially and has been used by other militaries. In addition to the .45 ACP (Automatic Colt Pistol), models chambered for .38 Super, 9 mm Parabellum, 7.65mm Parabellum, 9mm Steyr, .400 Corbon, and other cartridges were offered. The M1911 was developed from earlier Colt designs firing rounds such as .38 ACP. The design beat out many other contenders during the government's selection period, during the late 1890s and early 1900s, up to the pistol's adoption. The M1911 officially replaced a range of revolvers and pistols across branches of the U.S. armed forces, though a number of other designs have seen use in certain niches.

Despite being challenged by newer and lighter weight pistol designs in .45 caliber, such as the Glock 21, the SIG Sauer P220, the Springfield XD and the Heckler & Koch USP, the M1911 shows no signs of decreasing popularity and continues to be widely present in various competitive matches such as those of USPSA, IDPA, IPSC, and Bullseye.