Tests done during the middle to late 1880’s showed that the Gardner and Nordenfelt machine guns were better that the older Gatling guns by the Royal Navy and on the 16th of May 1881 they stated that the 5-barrel Gardener machine gun in .45 cal. would be introduced for general Naval service apart from the adoption of the 1 inch Nordenfelts. British service machine gun ammunition was designed in two distinct case forms, namely the Gatling and later form as the Gardner, Gatling and the second type, namely the 45 Martini Henry chamber. The former was issued in a number of different case lengths according to the particular mark number and was issued with a slimmer bottleneck form that the Martini Henry case. The two versions were not interchangeable.

This version is the ‘CARTRIDGE MACHINE GUN BALL GARDNER AND GATLING 0.45 inch MARK 2’. See also Labbett p. 78. This specimen is also the same as CFMG93(d) in Hoyem 2 p.115.