MOS Description and Mission
The 0331 Machine Gunner is the primary MOS for enlisted infantry Marines who operate man portable medium and heavy machineguns as part of the Infantry Battalions' weapons platoons and companies.
The Machine Gunner is responsible for the tactical employment of the 7.62 mm Medium Machine-Gun, the 50 cal., and 40mm Heavy Machine-Gun, and their support vehicle. Machine Gunners provide direct fire in support of the Infantry Rifle squads/platoons/companies. They are located in the weapons platoons of the rifle and weapons company in the infantry battalion. Noncommissioned Officers are assigned as team leaders and squad leaders/section leaders.