The Colt Rail Gun is a usa-made semi-automatic pistol chambered in .45 ACP, introduced in 2012. Primary use: Carry, Tactical. Type: Pistol Action: Semi-Automatic Caliber: .45 ACP Capacity: 8 Year introduced: 2012, USA Weight: 38 oz Overall length: 8.5" Status: Active Military use: Yes Intended use: Carry, Tactical