초록

A two part cartridge has a rearwardly recoiling inner piston and a choked orifice at its forward end to develop a blow-back thrust that will cycle a recoil operated automatic firearm. The piston operates by thrusting off the inner end wall of the firearm chamber in which the cartridge is loaded.

대표청구항 ▼

In combination with a firearm having a barrel with an inner bore and a firearm chamber 102, the firearm chamber 102 having an annular step 100 at its forward end, the inner diameter of such step bounding the inner bore of the barrel of the firearm, a cartridge 10 positioned within said firearm chamb

In combination with a firearm having a barrel with an inner bore and a firearm chamber 102, the firearm chamber 102 having an annular step 100 at its forward end, the inner diameter of such step bounding the inner bore of the barrel of the firearm, a cartridge 10 positioned within said firearm chamber 102, said cartridge comprising: (1) a cartridge case having a base end 16 and front end 26 and an inner diameter at said front end 26; (2) a source 14 for propellant gas within the cartridge 10; (3) a piston 30 having a substantially closed rearward end, wherein said rearward end is sealingly positioned within said cartridge case 12 at a location spaced from the base end 16 of the cartridge case 12 and defining a closed cavity 22 within the cartridge case 12, said cavity 22 containing the source for propellant gas, the piston 30 having a front piston end 40 bounded by an outer, annular shoulder 76 defining the forwardmost portion of the piston 30, said front piston end 40 extending forward of the front end 26 of the case 12, said annular shoulder 76 having a diameter that is larger than the inner diameter of the case 12 at its front end 26 and larger than the inner diameter of the step 100 at the forward end of the firearm chamber 102; and (4) gas passage means, extending from said closed cavity 22 through said piston 30, to permit gas generated within the cavity 22 subsequent to firing of the cartridge 10 to pass outwardly from the front piston end 40 of the piston, at least a portion of said cartridge case 12 being slidable on said piston 30, and means for limiting sliding displacement in the rearward direction of the case 12 with respect to said piston 30 upon firing of the cartridge 10.