Arm yourself with the Military Armament Corp 1014 Marine Pistol Grip 12 Gauge Semiautomatic Shotgun. It is semiautomatic with a 5-round capacity. The 18.5-inch barrel has an electroless marine nickel finish, and its stock is made of polymer. The chamber is 3 inches long. Military Armament Corp 1014 Marine Pistol Grip 12 Gauge Semiautomatic Shotgun - Shotgun Semi Automtc at Academy Sports