1864 - Gunner's Mate Chief established by General Order No. 36

1894 - Paygrades of First, Second, and Third Class Petty Officers
           established by General Order No. 409

1903 - Rating of Turret Captian established for Chief and First Class
          (Turret Gunner's Mates of lower paygrades remained general GM's)

1942 - WW2 Two new specialties added to the Gunner's Mate Rating
           Armorer & Powderman

1948 - GM General Service Rating Established for Paygrades E-4 through E-7

1948 - GM Emergency Service Ratings Established in Paygrades E-4
           through E-7

            1. GMA (ARMORER)
            2. GMM (MOUNTS)
            3. GMT(TURRETS) PAYGRADE E-6 & E-7

                *NOTE* At this time the rating of Turret Captain was
                  disestablished and incorporated into the GM rating as
                 GMT(Turrets)

1958 - Paygrades of E-8 & E-9 established

1961 - Emergency Service Ratings (GMA, GMM, GMT) disestablished

1961 - E-8 & E-9 Redesignated from General Service Rating to General
          Rating

1961 - Gunner's Mate Guns (GMG) and Gunner's Mate Missles (GMM)
          Service Ratings Established for paygrades E-4 through E-7

         GMG DUTIES - Operating repairing and maintaining all types of guns,
         rocket launchers, certain types of missle launchers, and their associated
         magazines and or handling equipment.

        GMM DUTIES -  Maitenance , testing, and firing of missles and their
        associated magazines and handling equipment.

1961 - Nuclear Weaponsman (NW) retitled to GMT.

1963 - NEC 0891 ASROC  specialist merged with GMT from the GMM
          rating

1986 - WT (Weapons Technician) Raing established from the GMT rating
          (NEC's dealing with Nuclear Weapons)

1987 - GMT(Technician)  Rating merger with the GMM(Missles) taking the
          Gunner's Mate Rate back to two ratings GMG & GMM

1987 - At the E-7 Level GMG & GMM merged to becom GMC

           GMC Duties - Responsible for all Gun and Missle Systems and their
            associated magazines and handling equipment.

1997 - The GMG and GMM ratings are merged at the E-1 through E-9 Level
           to become GM
 
 
 

2. GMM 3&2 VOL I NAVEDTRA 10188    PUBLISHED 1983

3. GMG 1&C NAVEDTRA 10186-D1 PUBLISHED 1981

4. GMM 1&C NAVEDTRA 10200-D PUBLISHED 1979

5. GMG1 NAVEDTRA 10292 PUBLISHED 1990
 
All information posted is believed to be correct if anyone has other sources of information please inform of the mistake and your reference source and changes will be made. I can be reach at e-mail guns@nia.attmil.ne.jp