OCSW The design forms part of the Objective Family of Small Arms, which includes the Objective Individual Combat Weapon,a personal weapon, a sniper weapon, and other mission-specific types. The OCSW is planned to replace most of the US Army's M2 0.50-caliber (12.7mm) heavy machine guns and MkE19 grenade launchers, and may also succeed a proportion of the M60 machine guns.