Gunner's mate

The United States Navy occupational rating of gunner's mate (GM) is given by the Bureau of Naval Personnel (BUPERS) to enlisted sailors. They must either complete school training or by showing they are familiar with the field of ordnance.
The Gunner's Mate school is held at Naval Training Center Great Lakes, Illinois. The school was originally very hands-on. It is now primarily conducted through self-study computer-based training (CBT). The training focuses on the operation, maintenance, and troubleshooting of Naval guns, missile launchers, and torpedoes. It has a strong emphasis on basic explosives, guidance and tracking systems, small arms, Naval ammunition classification, and safety. Upon completion of this school enlisted members often continue on to a specialized school. At the specialized school they learn a particular weapons system.
A GM will specialize in weapons such as the M500 shotgun, M60 machine gun, M14 rifle, M2 Browning machine gun, M9 pistol, M11 pistol, M16 rifle, M240 machine gun, M203 grenade launcher, M79 grenade launcher, M1911 pistol, M1 Garand, Mk 19 grenade launcher, Mk 18 Mod 0 Carbine Rifle, 5"/54 caliber Mark 45 gun, M242 Bushmaster chain gun, Vertical launching system, Missiles, , pyrotechnics, hand grenades, non-lethal weapons, force protection &amp; anti-terrorism, as well as operating shooting ranges, armories, and the storage and issue of ammunition.