The M1911A1 is the refined version of John Browning's original 1911, adopted by the US military in 1924. Features an arched mainspring housing, shorter trigger, longer grip safety spur, and relief cuts behind the trigger. Standard US military sidearm through the Vietnam era. Type: Semi-Auto Pistol Action: Single-Action Caliber: 45 ACP Capacity: 7 Year introduced: 1924, USA Weight: 39 oz Overall length: 8.5" Status: Discontinued Military use: Yes Intended use: Military, Duty, Collector