The M73 machine gun was a selective fire, gas-operated, belt-fed general purpose machine gun used by the United Nations Space Command during the Swarm War. As a general purpose or medium machine gun, the M73 bridged the gap between light and heavy machine guns, and found a wide range of uses within the branches of the UNSC, including but not limited to use by infantry, aircraft and ground vehicles. Chambered for the 9.5x60mm high velocity, full-sized rifle cartridge, the M73 supplemented weapons using lighter cartridges in squad-based combat, providing increased range and terminal effects compared to smaller calibre small arms and supporting infantry units with sustained heavy fire. The M73's weight made it significantly more unwieldy than assault rifles and light machine guns, although a