Abstract: A gas actuated cartridge, which is smokeless, flashless and noiseless in ration, contains a novel pusher cup of elastic material, such as butyl rubber. The pusher cup is folded back within itself and contains an exterior annular flange which fits into a groove in the bore of the cartridge case. A closure plug containing the propellant charge is threadably attached to the bore of the cartridge case and engages the interior of the cup in the flange portion to seal and anchor the cup in the bore. The elastic cup can propel a projectile by the unfolding action of the cup, and expands without rupture to contain the propellant gases and contracts when the volume of the gases reduces on cooling, whereby the cup shrinks back from the wall of the gun barrel and, hence, can be readily removed from the barrel.