Richard Gatling originally patented this weapon in 1862. After the Civil War, Gatling Guns came in .45, .50, and 1-inch calibers. The Fort Davis Gatlings were the model 1866. The Gatling gun was composed of ten barrels that rotated and fired by turning a hand crank that simultaneously fed cartridges from a large vertical hopper. The Gatling gun could fire 350 rounds a minute when it worked; however, the piece was prone to jamming. Designed as an anti-personnel weapon, the Gatling Gun saw very little service in the West.