sentences:  Designed primarily as a coaxial machine gun by the Rock Island Arsenal and produced by General Electric, the M73 was developed as a replacement for the M1919A4E1, M1919A5, and M37 machine guns that continued to serve in the immediate post–World War II environment.The "Machine Gun, 7.62-MM, M73" was officially adopted in 1959.It is an air-cooled, recoil-operated machine gun, but also using cartridge gasses to boost recoil.