Abstract: A lower receiver assembly of a rifle including a lower receiver having a magazine well formed thereon between a distal end and a proximal end, the lower receiver operable to receive a trigger assembly including a trigger, a hammer, and a firing pin. The lower receiver can include an operating rod retention tab coupled with an upper surface of the receiver and the operating rod retention tab extends above the upper surface and is operable to be received in a groove formed in a receiver of an upper receiver.

Abstract: A bolt carrier for a firearm having a first end configured to slidably engage with a bolt along a first axis, the bolt carrier comprising, a cam pin, a cam slot for movably constraining the cam pin, and a bolt operatively connected to a cam pin, wherein cam pin and cam slot at least partially constrain the rotational and linear movement of the bolt with relation to the bolt carrier. The cam slot further includes a first portion for constraining the linear motion of the cam pin and the bolt and a second portion for controlling rotational movement of the bolt while guiding the cam pin along the cam slot. The cam slot further includes a third portion a third portion for controlling the linear motion of the bolt.

Abstract: A firearm for firing cased telescoped (CT) ammunition cartridges that includes a split chamber configured to fully support a CT cartridge when it is fired, and that includes i) a dynamic rear chamber portion defining a pocket in a face of a bolt, and ii) a static front chamber portion that is integral to the barrel and separate from the bolt. A cartridge extraction mechanism engages the CT cartridge prior to the CT cartridge being fired, and holds the CT cartridge in the pocket in the bolt face as the bolt moves rearward to pull the CT cartridge out of the static front chamber portion and into an ejection position. An ejector is operable to eject the CT cartridge from the pocket in the face of the bolt when the CT cartridge reaches the ejection position.

Abstract: A weapon for firing cased telescoped (CT) ammunition includes a barrel, a chamber member and a carrier assembly. The chamber member defines a chamber for a CT round for firing, and translates between a firing position aligned with the barrel and an ejection/loading position. The chamber member is spring-biased toward the firing position. Dual-feed structure provides for both a magazine mode as well as a belt feed mode of operation.

Abstract: A firearm for firing cased telescoped (CT) ammunition cartridges that includes a split chamber configured to fully support a CT cartridge when it is fired, and that includes i) a dynamic rear chamber portion defining a pocket in a face of a bolt, and ii) a static front chamber portion that is integral to the barrel and separate from the bolt. A cartridge extraction mechanism engages the CT cartridge prior to the CT cartridge being fired, and holds the CT cartridge in the pocket in the bolt face as the bolt moves rearward to pull the CT cartridge out of the static front chamber portion and into an ejection position. An ejector is operable to eject the CT cartridge from the pocket in the face of the bolt when the CT cartridge reaches the ejection position.

Abstract: A weapon for firing cased telescoped (CT) ammunition includes a barrel, a chamber member and a carrier assembly. The chamber member defines a chamber for a CT round for firing, and translates between a firing position aligned with the barrel and an ejection/loading position. The chamber member is spring-biased toward the firing position. The carrier assembly carries the firing pin and (1) performs a recoil in which a carrier and rammer move rearward from a battery position to bring the next CT round into a ramming position and to move the chamber member from the firing position to the ejection/loading position, and (2) performs a counter-recoil to return to the battery position and cause the rammer to push the next CT round into the chamber. The chamber member is released for biased return to the firing position for a next firing cycle.

Abstract: A bolt carrier having a first gas port, wherein the first gas port provides fluid communication between an interior and an exterior of the bolt carrier; a second gas port, wherein the second gas port provides fluid communication between an interior and an exterior of the bolt carrier; and a third gas port, wherein the third gas port provides fluid communication between an interior and an exterior of the bolt carrier.

Abstract: An operating system for a firearm includes a body, configured to be mounted to a firearm, having an interior space, a front, and an opposed rear. A piston is carried within the interior space for reciprocation between a forward position toward the front and a rearward position toward the rear. A gas port is formed proximate to the front of the body, and an outlet is formed proximate to the rear of the body. First and second gases flank the piston. Those first and second gases are isolated from each other. The piston moves to the rearward position in response to expansion of the first gas, thereby imparting movement of the second gas through the outlet. The piston also moves to the forward position in response to contraction of the first gas, assisted by a spring.

Abstract: An improved gas key assembly for a fire arm, such as an AR 15 or a M4 rifle, having a gas key fastened by fasteners on a bolt carrier assembly where the gas key moves with the bolt carrier when the fire arm is fired, wherein the gas key has a slot for receiving a key element in the slot and the key element has a stem which is seated in the slot and a rail which overlays the fasteners to removably secure the gas key to the bolt carrier and holds gas key resisting unintended separation of the gas key from the bolt carrier. Also the invention includes a method for securing a gas key to a bolt carrier in such a fire arm.

Abstract: A firearm operating system for self-loading firearms includes a bolt body having a forward bolt bearing, a piston and an aft bolt bearing arranged around the bolt body; a bolt carrier slidingly receiving the bolt body in a longitudinally-oriented cylinder, the cylinder extending from a forward end of the bolt carrier into the bolt carrier a predetermined distance, the bolt carrier having a tubular aft carrier bearing, wherein the bolt is slidingly captured in the cylinder of the bolt carrier and borne on the two bearings of the bolt body, wherein the forward bearing of the bolt body is borne on the cylinder of the bolt carrier, wherein the aft bearing of the bolt body is borne on the aft bolt carrier bearing, wherein a gap is formed between the piston and the cylinder, and wherein the piston and the cylinder do not contact each other.

Abstract: An ammunition magazine follower comprises a main bottom member defining an upper and lower surface. The upper surface comprises a substantially flat portion and a parallel ridge portion, where the flat and ridge portions are arranged in the longitudinal direction of the main bottom member. One or more guides are arranged on the lower surface for guiding the follower in the magazine. An urging member such as a spring, when installed in a magazine, urges the follower away from the magazine bottom. The guide comprises at least one end wall projecting perpendicularly away from the lower surface of the main bottom member. The end wall comprises a moveable tap, where the upper part of the tap is biased and projects partly above the upper surface of the main bottom member.

Abstract: A fixed-barrel, gas-operated firearm having its barrel concentrically mounted within a pressure tube enclosing substantially all of the moving parts of the firearm's action. A gas cup reciprocates under the influence of propellant gas pressure when the firearm is fired, driving slide members that link the pressure cup to the firearm's bolt rearward within the pressure tube, unlocking the breech, rotating and retracting the bolt, discharging the spent cartridge casing and then advancing the bolt to chamber a new cartridge.

Abstract: A cam pin system, includes a cam pin comprising a first cylindrical portion having a first length and a first diameter and a second cylindrical portion concentric with the first cylindrical portion and having a second diameter larger than the first diameter, the second cylindrical portion comprising a through-hole to accommodate the passage of a firing pin. The system includes an end plate detachably connected to the first cylindrical portion of the cam pin, a cylindrical bushing encircling the first cylindrical portion and having an outside diameter approximately equal to the second diameter and a bushing length approximately equal to the first length, and lubricant between the cylindrical bushing and the first cylindrical portion. The cam pin system is configured so that the cylindrical bushing can rotate freely about the first cylindrical portion.

Abstract: A fixed-barrel, gas-operated firearm having its barrel concentrically mounted within a pressure tube enclosing substantially all of the moving parts of the firearm's action. A gas cup reciprocates under the influence of propellant gas pressure when the firearm is fired, driving slide members that link the pressure cup to the firearm's bolt rearward within the pressure tube, unlocking the breech, rotating and retracting the bolt, discharging the spent cartridge casing and then advancing the bolt to chamber a new cartridge.

Abstract: Disclosed is a bolt assembly that may include several lands that extend along the forward end of the bolt assembly that occupy only about 1 percent to about 12 percent of the surface area of the forward end. Also disclosed is a bolt carrier that defines a cam path that includes an increased unlock dwell time of approximately twice the unlock dwell time provided by a cam path shaped like a standard M-16 cam path. Also disclosed is a bolt carrier that includes a protrusion at a forward end of the bolt carrier with a bore that extends through the protrusion and the bolt carrier at a substantially constant bore diameter, where the protrusion is sized to be received in the barrel extension extends approximately one hundred thousandths of an inch from the end of the bolt carrier.

Abstract: A rifle having a receiver with an integral hand guard and a barrel. The barrel is connected to the receiver. The hand guard extends over and surrounds the barrel. A removable hand guard is attached to the receiver by an attachment that stably holds the removable hand guard to the receiver. The attachment is arranged for allowing detachment and removal of the removable hand guard from the receiver without removal of fasteners.

Abstract: Breech guides for use with breech assemblies and firearms including such breech guides are disclosed. An example breech guide for use with a breech assembly of a firearm includes a support element positioned within the breech assembly and a control element on the support element, the control element is adapted to control a cartridge-feeder mechanism of the firearm. The example breech guide includes a guide element on the support element. The guide element is adapted to guide the breech assembly relative to guide rails of the firearm. The support element extends along an axis of symmetry substantially perpendicular to a bore axis. The control element and the guide element being substantially coaxially positioned relative to the axis of symmetry.

Abstract: A bolt carrier impingement device for a firearm has a body including a rearward facing surface. The rearward facing surface of the bolt carrier impingement device abuts the forward facing surface of the bolt carrier, thereby transferring all rearward force imparted to the front of the bolt carrier impingement device through only the forward facing surface of the bolt carrier. The rearward facing surface of the body may be a notch and the forward facing surface of the bolt carrier may be a buttress. The bolt carrier may include a cam aperture formed through a top surface rearward of the forward facing surface. A forward most portion of the impingement device may terminate in front of the cam aperture. A bottom surface of the body may form a slot that forms an arch over the cam aperture.

Abstract: An anti-rotation feature incorporated between a cotter pin and a sub caliber action device installable within an upper receiver of a firearm. A receiver plate exhibits a notched interior for seating a bolt in reciprocating fashion. A chamfer formed in a side of the bolt intersects a length extending channel of the bolt for seating within the notched interior. The chamfer seating a head of the cotter pin to prevent rotation during bolt travel. A rearward support sleeve seats an opposing guide rod associated with the receiver plate and in order to maintain the bolt assembly. A firing pin exhibits a notch at a location along its shaft and, upon installation within an interior aperture of the bolt, is retained in position by the cotter pin. The firing pin is configured so as to exhibit a reduced diameter end projection upon which is supported a coil spring.

Abstract: Locking systems for use with firearms are described. An example locking system for use with a firearm includes a breechblock carrier and a lock spring mechanism that includes a piston. The breechblock carrier is configured to interaction with the piston. Additionally, the example locking system includes a first aperture. The piston is configured to expel fluid through the first aperture when the breechblock carrier retracts.

Abstract: A bolt carrier impingement device for a firearm has a body including a rearward facing surface. The rearward facing surface of the bolt carrier impingement device abuts the forward facing surface of the bolt carrier, thereby transferring all rearward force imparted to the front of the bolt carrier impingement device through only the forward facing surface of the bolt carrier. The rearward facing surface of the body may be a notch and the forward facing surface of the bolt carrier may be a buttress. The bolt carrier may include a cam aperture formed through a top surface rearward of the forward facing surface. A forward most portion of the impingement device may terminate in front of the cam aperture. A bottom surface of the body may form a slot that forms an arch over the cam aperture.

Abstract: The present invention is a direct impingement gas operated firearm, having a longitudinally translatable bolt and a rearward locking mechanism coupled to the bolt. The rearward locking mechanism includes a locking lug, laterally shiftable by gas means from a locked position to an unlocked position, and a reinforcement, fixed with respect to the bolt. In the locked position the lug interferes with the reinforcement such that the bolt is restrained from moving longitudinally, and in the unlocked position the bolt is free to longitudinally translate within the firearm.

Abstract: A semi-automatic or automatic rifle is provided. The semi-automatic or automatic rifle includes a receiver having an integral hand guard portion, a barrel having a bore. The bore is removably connected to the receiver, the hand guard portion extending over and surrounding the barrel, an indirect gas operating system has a gas block and a piston. The gas block has a cylinder, the gas block is fitted to the barrel, the cylinder is in communication with the bore. The piston has a piston end and a striking end, the piston end is fitted to the cylinder and has a bolt carrier having a striking surface. When a cartridge is fired, gas displaces the piston end and causes the striking end to strike the striking surface displacing the bolt assembly, wherein, the cylinder and the piston are together removable as an assembly from the firearm without disassembly of the rifle.

Abstract: Locking systems for use with firearms are described. An example locking system for use with a firearm includes a breechblock carrier and a lock spring mechanism that includes a piston. The breechblock carrier is configured to interaction with the piston. Additionally, the example locking system includes a first aperture. The piston is configured to expel fluid through the first aperture when the breechblock carrier retracts.

Abstract: The present invention is a direct impingement gas operated firearm, having a longitudinally translatable bolt and a rearward locking mechanism coupled to the bolt. The rearward locking mechanism includes a locking lug, laterally shiftable by gas means from a locked position to an unlocked position, and a reinforcement, fixed with respect to the bolt. In the locked position the lug interferes with the reinforcement such that the bolt is restrained from moving longitudinally, and in the unlocked position the bolt is free to longitudinally translate within the firearm.

Abstract: A semi-automatic firing carbine anti-jamming cartridge loading system is provided wherein no feed lips or a portion of said feed lips are removed, wherein the cartridge to be loaded is fed to the carbine breech along a feed ramp. A bolt enclosing the firing pin includes a pivot plate mounted on the bolt nose, rotating about an axle. A recess formed in the bolt nose provides spacing for the pivot plate to rotate about said axle. If the firing pin protrudes through an aperture formed in the pivot plate, while the pivot plate is still in its collapsed state, then the weapon will jam by the firing pin hanging on the top part of a rim portion of the next loading round, thereby thwarting attempts at reconfiguring the weapon, that employs my novel system, to be re-converted as a fully-automatic weapon.

Abstract: A direct drive retrofit system for use with an M-16 or AR-15 rifle for conversion from an impingement system comprising: a gas block, the gas block having a barrel bore and a gas plug bore; a gas plug, the gas plug being inserted into the gas plug bore from the muzzle end; a bolt carrier key, the bolt carrier key being configured to mount directly to a bolt carrier; a rod, the rod being manufactured from a single continuous material stock; and a biasing means; wherein, the rod can be uninstalled without removal of a hand guard or the gas block by extracting the gas plug from the gas plug bore from the muzzle end, the actuating means releasing the rod, the rod being freely extracted thereafter by a user in a single piece.

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.

Abstract: A firing pin for a firearm, more particularly for a firearm provided with a gas-operated bolt and bolt-carrier, the firing pin being disposed slidably in a longitudinal bore in the bolt. The firing pin of the invention has its shoulder abutment, which limits the stroke of the firing pin, provided with longitudinal apertures, such as slots or holes, preferably disposed at an angle to the longitudinal axis of the firing pin, which provide passageways for the pressure gas operating the bolt-carrier and leaking along the stem of the firing pin. Carbon, or other dirt, is thus prevented from being deposited on the firing pin stem, more particularly at the shoulder abutment.

Abstract: A firearm for firing caseless ammunition includes a barrel, a receiver, a bolt, and a firing pin. The bolt includes laterally open pockets for receiving a projectile and a separate propellant cartridge. The bolt carries an extractor to extract unspent projectiles. The bolt drives a locking collar to lock itself in forward position. The locking collar is unlocked by the recoil-action of the firing pin. The firing pin is driven by a spring biased hammer; the firing pin then drives the hammer by recoil action, causing the hammer to unlock the locking collar. A gas seal for the firing pin includes a deformable ring which is deformed by ignition gas pressure into sealing engagement with the firing pin. An anti-recoil muzzle at the discharge end of the barrel has a reaction surface thereof cleaned of combustion deposits by a plurality of bristles extending from the barrel. A propellant cartridge comprises a plurality of telescoping nitrocellulose jackets which form a propellant chamber and a primer compartment.

Abstract: A firearm, particularly a short firearm for firing caseless ammunition, comprises a housing having a sleeve fixed therein with first and second spring members which are biased against a projection on the gun barrel in order to hold it against axial displacement in each direction. The barrel includes a breech portion with a magazine chamber, and cartridges are moved out of the magazine chamber into a cartridge chamber by a gas piston which is displaceable in a lock member which, together with the gas piston, seals the space in the cartridge chamber behind the cartridge during firing. The lock member includes projections which are engaged behind recesses of the rear breech portion of the barrel.