Abstract: A muzzle ejecting sabot cartridge firearm system for use in a weapon having an elongated gun barrel, an action mechanism, and an elongated bolt mounted within the bore of the action mechanism. The bore of the action mechanism and the bore of the gun barrel are in co-axial alignment and the forward end of the action mechanism is in communication with the rear end of the gun barrel. The bolt has an elongated bore extending inwardly from its base end that communicates with a relieved portion in the front face of the bolt to allow passage of gases released from a cartridge that has been fired. The diameter of the bore of the action mechanism is greater than the diameter of the bore of the gun barrel thereby forming a shoulder at the front end of the action mechanism that functions to capture the peripheral rim along the back end of a sabot cartridge at the initial stage of firing the cartridge.