GSR

Overview
The Granite Series Revolution (GSR) pistol is a .45 caliber pistol based on the classic 1911 design. Designed by the Swiss firearm manufacturer SIG Sauer, some variations of the pistol feature an accessory rail for mounting objects such as tactical lights and lasers. Standard variants feature a 5-inch barrel and a 4.5 pound single-action trigger.

In MGS
The GSR is the primary sidearm of PMC soldiers in MGS4; it is also available to Snake.