The GSR (Granite Series Rail) Revolution was SIG's tactical full-size 1911 with an integral accessory rail machined into the frame below the dust cover. Among the first 1911s designed from the ground up with a factory rail rather than a traditional dust cover profile. Type: Pistol Action: Semi-Automatic Caliber: .45 ACP Capacity: 8 Year introduced: 2004, Germany/USA Weight: 41 oz Overall length: 8.75" Status: Discontinued Intended use: Tactical, Duty