The M1911A1, a variant model of the original M1911, remained in the US military for nearly three-quarters of a century. It was adopted by the US Army as a sidearm in 1911, and remained virtually unchanged until it was replaced by the M9 Beretta in 1985.
Colt first introduced the swinging link method of breech locking, which has since been extensively copied by other pistol manufacturers worldwide. The barrel locks to the slide by means of two lugs on its upper surface. After firing, the barrel and slide move backward due to recoil.
Minor modifications were made to the M1911 in 1926 and it was re-designated the M1911A1. The original M1911 had a distinctive hammer spur which allowed cavalrymen to cock the hammer on their leg while riding. After WWI this feature was deemed obsolete and the hammer spur was shortened. Also, the rear of the butt was more curved, and the trigger was made smaller and grooves added. The M1911A1 has several safety features, one being on the pistol grip which must be pushed in or the pistol will not fire.
Rangers have carried the M1911A1 .45 pistol into combat during World War II, Korea, Vietnam, Iran and Grenada. In the early anti-terrorist training days, the M1911A1 was a true workhorse. It only holds seven rounds, eight with one chambered, but we were deadly accurate and learned how to change magazines quickly. It's a an extremely durable pistol with few moving parts, and easy to work on and repair. It can literally be dropped in mud or sand and still fire without malfunctioning. Many in the Special Operations community still revere the 1911A1 as the superior choice for dependability and stopping power.