The GM Rating

The Gunner's Mate rating was officially established in 1794, and is one of the United States Navy's original ratings. Gunner's Mate is also one of the eight original Chief Petty Officer ratings. The Torpedoman (TM - Surface) rating merged with the GM rating on October 1, 2007.

The Navy's computerized personnel system associates the rating name with an alphanumeric Navy Occupational Specialty (NOS) code. For GM, the NOS is B320.

Gunner's Mates are responsible for the operation and maintenance of guided missile launching systems, underwater explosive weapons such as torpedoes, rockets and missiles, and the systems used to launch them, gun mounts and other ordnance equipment as well as small arms magazines. They work with electrical and electronic circuitry: mechanical, hydraulic and pneumatic systems.

Gunner's Mate class "A" school is located in Great Lakes, Illinois, and the school is approximately 27 weeks in duration. The GM rating requires a 60 month (5 year) service obligation for those leaving for boot-camp in Fiscal Year 2018 and beyond.

Gunner's Mate (NOS B320)

Gunner's Mates operate and maintain guided missile launching and torpedo launching/handling systems, rocket launchers, gun mounts and other ordnance systems and equipment. They train and supervise crews in the use of all types of ordnance equipment, from large caliber guns and missile systems to small arms. GMs stow, secure, requisition and reclassify explosives, and operate and maintain magazine flooding and sprinkler systems. They make mechanical, electrical and electronic casualty analysis using technical publications, blueprints, schematics and circuit diagrams; they repair, maintain, test and calibrate ordnance equipment.

GMs repair, maintain, test and calibrate micro processing equipment, and use and care for common hand tools, special tools and soldering equipment. They perform preventive and corrective maintenance on hydraulic and pneumatic systems and components associated with launching systems. GMs interpret color coding to determine values of capacitors and resistors, and tracing internal connections of power and audio transformers, chassis wiring and multi-conductor cables.

They operate and maintain night optical devices, and operate optical scanning and marking devices to label, identify and report explosives' utilization/expenditure. They serve as team member performing inspections and final closeout checks on weapons, and install and remove torpedo exploder mechanisms.

Career Sea - Shore Rotation Chart

Gunner's Mate Rating's Sea (SEA) Shore (SH) Rotation (months)
GM 49 6048 4836/36

Sea tours and shore tours for Sailors that have completed four sea tours will be 36 months at sea followed by 36 ashore until retirement.

Qualifications, Interests, and Working Environment

Gunner's Mates should be capable of learning how to use test equipment and applicable hand tools to perform casualty analysis and arrive at solutions for problems in solid state, digital electronics, microprocessor logic, electrical, hydraulic and mechanical equipment. They should also have good memories, the ability to do detailed work, perform repetitive tasks and keep accurate records.

Due to the sensitive nature of some of the technical duties, the GM rating has special eligibility standards for reliability, integrity and trustworthiness. GMs must be U.S. citizens eligible for a security clearance. Adversely adjudicated drug abuse offenses will not receive waiver consideration. Normal hearing and color perception are required.

Gunner's Mates work in almost every kind of Navy environment: ship, shore, in the United States or overseas. Their work and specialties may involve indoor or outdoor situations, clean or dirty work, deck or shop, and any kind of climate or temperature. They work alone or with others independently or closely supervised. Their work can be both mental and physical. GM's ASVAB Test requirement.

Opportunities are excellent for qualified applicants. About 4,500 men and women work in the Gunner's Mate rating.

Personnel in the Gunner's Mate rating are paid allowances (BAH, BAS, etc. if eligible) and billet pay (sea pay, etc. if eligible), and military basic pay based on years of service and paygrade.

Credit Recommendations

The American Council on Education recommends that eight semester hours in principles of technology, two in hydraulics and pneumatics, and one in industrial safety be awarded in the vocational certificate category and four semester hours in basic AC/DC circuits and three in solid state electronics be awarded in the baccalaureate/associate degree category.