Abstract: An inert, reuseable cartridge which is fully compatable with the cycling ramming operations of an automatic gun mount comprising a cartridge case having an inert projectile and dummy fuze welded thereto. A sliding mass is disposed within the cartridge case and coupled to an adjustable shock absorber which dissipates the energy of the sliding mass during ramming to duplicate the unique rebound response of an in-service projectile. The exterior dimensions, center of gravity, and total mass properties are equivalent to those of the in-service cartridge.