Marine students of the Battle Skills Training School machine gunner course with 2nd Marine Logistics Group dive for an M240B medium machine gun during a simulated enemy attack prior to a live-fire exercise aboard Camp Lejeune, N.C., Oct. 4, 2013. The service members learned the characteristics; including maximum ranges, rates of fire and the nomenclature, of M240Bs, MK19 Grenade launchers and M2 Browning .50-caliber machine guns.