Weatherby, Inc. is an American firearms and ammunition company founded in 1945 by Roy Weatherby and based in Sheridan, Wyoming. The company is known for high-velocity proprietary cartridges and the bolt-action rifles chambered for them. The Mark V bolt-action rifle is the flagship model. It uses a 54-degree bolt throw for faster cycling and hand-lapped barrels. Proprietary Weatherby cartridges include the .300 Weatherby Magnum and .257 Weatherby Magnum, which deliver higher velocities than standard chamberings of similar bore diameter. The Mark V is used primarily by big-game hunters and long-range shooters. Weatherby also produces shotguns including the Element and SA-08 series, chambered for upland hunting, waterfowl, and sporting clays.