Patent ID: 6253682
Filing Date: 2001-07-03
Classification: F42B

Abstract:
A cartridge for use in a firearm, said cartridge being capable on firing of recycling the firearm; the cartridge comprising a casing having a projectile mounted in a front end thereof so as to extend forwardly therefrom, the casing being formed with a stepped passage therethrough, the passage having a rearward larger diameter section, a narrower intermediate section and a tapered forward section which receives a trailing end of the projectile;a core member disposed in the stepped passage, the core member having a peripheral flange at a rearward end thereof, which flange extends rearwardly of the casing, and a forward facing piston surface and a forward portion; the forward portion of the core member being slidably received in and blocking the narrower intermediate section in an inactivated condition of the cartridge;the core member having a defined therein a first expansion chamber to receive propellant gas from a primer, at least one outlet opening from said chamber through said forward facing piston surface into the passage rearwardly of a step between the rearward larger diameter section and the narrower intermediate section to allow gas to flow from the first expansion chamber into a second expansion chamber defined between the core member and the passage rearwardly of the step;such that on actuation of the primer, propellant gas is released into the first expansion chamber and then the second expansion chamber, wherein the second expansion chamber expands and propels the core member rearwardly to move the forward portion to unblock the narrower intermediate section and to allow gas to flow therethrough to eject the projectile from the tapered forward section of the passage, and wherein propulsion of the core member rearwardly serves to recycle the firearm.