The Colt M1911 is a single-action, recoil-operated, semi-automatic pistol chambered for the .45 ACP cartridge. The pistol's formal U.S. military designation as of 1940 was Automatic Pistol, Caliber .45, M1911 for the original model adopted in March 1911, and Automatic Pistol, Caliber .45, M1911A1 for the improved M1911A1 model which entered service in 1926. The designation changed to Pistol, Caliber .45, Automatic, M1911A1 in the Vietnam War era.

John Moses Browning was an American firearm designer who developed many varieties of military and civilian firearms, cartridges, and gun mechanisms, many of which are still in use around the world. He made his first firearm at age 13 in his father's gun shop and was awarded the first of his 128 firearm patents on October 7, 1879, at the age of 24. He is regarded as one of the most successful firearms designers of the 19th and 20th centuries and a pioneer of modern repeating, semi-automatic, and automatic firearms.