Originally manufactured by Firestone as a 57mm recoilless anti-tank rifle, this M18 has been converted to a 50 caliber single shot conventional rifle. Originally developed in the 1940s, the M18 was a crew-served anti-armor/anti-emplacement weapon that saw use into the Korean War, which could be operated from a tripod or shoulder fired as needed. The Firestone markings are present on the front of the receiver, with a telescoping monopod and a combination shoulder rest and rear bipod assembly.