Abstract: The invention relates to an upper receiver for a firearm, comprising a supporting part, which supports a barrel bushing for receiving a barrel, a guide for a longitudinally movable breech carrier, and an anchor for a sight. The guide for the breech carrier is formed on the underside of a rail block preferably made of metal which has the anchor for the sight on its upper side, and the supporting part is also preferably made of metal and mounted both to the barrel bushing and to the rail block via removable fasteners.

Abstract: A buffer tube for a firearm can include a body defining an interior cavity for receiving a buffer spring, and a rail disposed on and/or formed from the outer surface of the body. The rail can include one or more pin holes configured to receive a pin of a stock to lock the stock in a position, and a trunk opening defined at an end of the rail forming a first rail sidewall and second rail sidewall configured to receive a trunk of an actuator. The first and/or second rail sidewalls can include a slot defined therethrough configured to receive a pin associated with the trunk of the actuator to linearly guide the actuator. The rail can include a slide bar channel defined through at least a portion of the rail and configured to allow a slide bar to slide therein relative to the one or more pin holes to urge a pin out of a respective pin hole and/or to block a pin from being received by the pin holes.

Abstract: A firearm magazine includes an elongated tube defining a tube axis and having an upper end with feed lips and an opposed lower end. The tube has elongated front, rear, left and right side walls. A closure element is a bottom cap removably connected to the lower end of the tube and includes a latch movable between a retention position wherein the closure element is secured to the tube, and a released position wherein the closure element is removable from the tube. The closure element includes a spring loaded latch biased upward to lock into its retention position, and the closure element is slidably receivable onto the lower end of the tube by movement transverse to the tube axis in a removal direction. The latch is on a tube side opposite from the removal direction and configured to abut the tube to prevent removal when locked in its retention position.

Abstract: The present device is a shortened recoil system designed to replace the AR-15 type recoil system, comprising the standard recoil systems of many commonly used rifles including the AR-10, AR-15, M-16 and M-4. This shortened recoil system removes or replaces the parts of the traditional recoil system located in the stocks of these rifles and place the entire recoil system within the receiver, while maintaining the alignment of the recoil system with the barrel of the rifle. A major advantage of the present system is that it allows the rifle to be fired with a folded stock or even with no stock at all, as no part of the present recoil system is located within the stock.

Abstract: The present device is a shortened recoil system designed to replace the AR-15 type recoil system, comprising the standard recoil systems of many commonly used rifles including the AR-10, AR-15, M-16 and M-4. This shortened recoil system removes or replaces the parts of the traditional recoil system located in the stocks of these rifles and place the entire recoil system within the receiver, while maintaining the alignment of the recoil system with the barrel of the rifle. A major advantage of the present system is that it allows the rifle to be fired with a folded stock or even with no stock at all, as no part of the present recoil system is located within the stock.

Abstract: A bolt catch assembly for use with a firearm including a receiver with an exposed receiving chamber and an underside engageable magazine. The assembly includes a bolt catch actuator housing supported in seating fashion relative to the receiving chamber and communicating with an attachable magazine. A catch actuator is supported in elevatable fashion relative to an end of the actuator housing. A follower component is upwardly and biasingly disposed within the magazine and which, upon contacting the catch actuator, displaces an associated bolt catch of the firearm in an upper and bolt restraining position.

Abstract: An ambidextrous magazine release for a firearm is provided for a firearm having a magazine well configured to operatively receive a magazine having a side-locking recess received within the well. The ambidextrous magazine release comprises a linkage moveable between an engaged position and a disengaged position having a lock pin configured to be received in a side-locking recess of a magazine operatively received in the magazine well with the linkage in the engaged position and to clear the side-locking recess with the linkage in the disengaged position. An actuator is provided on the firearm comprising a bar having a opposing push surfaces extending between a right and left side of the firearm. An interface is provided between the linkage and actuator with the interface being configured so that as either of the opposing push surfaces of the bar is pushed by a user, the linkage is moved between the engaged and the disengaged position.

Abstract: A magazine support reinforcement for a machine gun having a receiver. A magazine support is attached to the underside of the receiver. The magazine support reinforcement is connected to the magazine support. The reinforcement includes a front support, a rear support and a fastener for fastening the front support to the rear support. The front and rear supports include bracing members having a generally concave side and a lug portion.

Abstract: An improved magazine for use in existing firearms comprises a housing, a follower, a spring, a spring hold and a cap. The housing comprises protruded surfaces for structural strength and a projection that acts as a stop member to define the maximum insertion of the magazine into the firearm magazine well. The follower comprises two follower legs and a spring retainer, and travels up and down the housing. The perimeters of the follower and follower legs mirror the internal profile of the magazine housing for a well-defined travel path within the magazine housing. The spring hold comprises a spring retainer and a round protrusion that locks it into the cap via a circular cut. The cap comprises flanges that slide into the slots against the end stop at the bottom of the housing.

Abstract: An improved base pad for a firearm magazine that more securely attaches to the bottom of a magazine tube in a manner which is easier and faster to attach or remove therefrom when cleaning the magazine. The improved base pad has a body member with a pair of ends and a pair of sides. The sides each have a groove configured to slidably receive, preferably snugly, the lips at the bottom of a standard magazine tube. One end of the base pad has an outwardly extending section with an upwardly facing, generally planar face. A securing mechanism at the outwardly extending section has an upwardly disposed projection that selectively engages one wall of the magazine tube to secure the base pad thereto when in its engaged position and allows removal of the base pad when in a disengaged position. In a preferred embodiment, the securing mechanism is a detent device.

Abstract: A preferred embodiment of a firearm cartridge clip is disclosed, in which the clip has an elongated housing extending from an open top end to an enclosed bottom end defining an elongated cartridge storage chamber. The clip has a cartridge support seat mounted in the chamber above a separate elevator element. A chamber compression spring is mounted in the chamber between a base at the bottom end and the elevator element to urge the elevator element upward. A separate movement-restraining means is associated with the cartridge support seat to resist downward movement of the seat from the opening at the top end. The clip has a loading facilitating means for selectively rendering the compression spring ineffective to urge the seat upward to thereby reduce the manual effort required to load the clip.

Abstract: An automatic firearm with a bolt assembly which is moveable along a bolt assembly motion path between a closed position and an open position, a magazine which advances cartridges by spring force across the bolt assembly motion path into this motion path, and a lock which only allows the first cartridge of magazine to advance into the bolt assembly motion path when the bolt assembly is situated in or near its open position, is disclosed. The lock is preferably created by a plate that extends parallel to the bolt assembly motion path and is mobile in its direction of extent, is pushed between the first cartridge and the bolt assembly motion path, and holds back the cartridge until the bolt assembly has reached or almost reached its open position.

Abstract: A lightweight weapon housing system is disclosed for a self-loading firearm. The weapon housing includes an outer and an inner housing. A wall structure in the weapon housing reinforces the magazine chamber and transmits the transverse forces arising in the magazine into an inner housing, which suffers any resulting deformation and which can be exchanged in a simple manner should deformation result.

Abstract: An M16 type rifle capable of being fired in automatic or semi-automatic mode is disclosed utilizing a blow-back system with a forcing cone breech and a matching conical bolt face. The blow-back bolt assembly of the present invention allows elimination of the troublesome and easily fouled gas operating system of the conventional M16 rifle and further allows the rifle to be chambered for short low-pressure pistol cartridges such as the 45 ACP and the 40 S&W.

Abstract: An M16 type rifle capable of being fired in automatic or semiautomatic mode is disclosed utilizing a blow-back system with a forcing cone breech and a matching conical bolt face. The blowback bolt assembly of the present invention allows elimination of the troublesome and easily fouled gas operating system of the conventional M16 rifle and further allows the rifle to be chambered for short low-pressure pistol cartridges such as the 45 ACP and the 40 S&W.

Abstract: An inertia striker assembly including a striker and a U-shaped spacer straddling the striker, both the striker and the spacer being free to slide axially and independently within a cylindrical bore in a slide body. The U-shaped spacer transfers energy from a striker spring to the striker to propel the striker from a cocked position toward a firing position. Movement of the U-shaped spacer is arrested by engagement of the spacer with an abutment surface within the bore allowing the striker to complete its travel to the firing position under its own inertia.

Abstract: An automatic firearm of especially simple construction and easy maintainability, having an adjustable cyclic firing rate. The firearm has a receiver with an upper and lower portion. The upper portion defines a cavity in which a bolt assembly reciprocates. The reciprocation is maintained by a single compression spring in the cavity, and the length of the cavity, and compression of the spring, are adjustable to vary the cyclic firing rate. The firearm includes an especially simple trigger group arrangement. The lower receiver portion is structured to protect the trigger group. Also disclosed is an especially simple, yet practical ejector mechanism.

Abstract: An automatic firearm of especially simple construction and easy maintainability, having an adjustable cyclic firing rate. The firearm has a receiver with an upper and lower portion. The upper portion defines a cavity in which a bolt assembly reciprocates. The reciprocation is maintained by a single compression spring in the cavity, and the length of the cavity, and compression of the spring, are adjustable to vary the cyclic firing rate. The firearm includes an especially simple trigger group arrangement. The lower receiver portion is structured to protect the trigger group. Also disclosed is an especially simple, yet practical ejector mechanism.

Abstract: The present invention relates to a firearm, generally of the automatic or semi-automatic type, having a reciprocating breech block normally biased into closed position by a primary recoil absorption system including a spring, the improvement comprising providing a secondary spring-biased recoil absorption system cooperating with the primary one during a portion of the retraction stroke of the block to slow down the movement of the latter before becoming inactive while the primary system slows the block to a stop and reverses its direction and then becoming active to once again cooperate with the primary system during a portion of the return stroke of the block to speed up its return to its original position.

Abstract: An automatic firearm of especially simple construction and easy maintainability, having an adjustable cyclic firing rate. The firearm has a receiver with an upper and lower portion. The upper portion defines a cavity in which a bolt assembly reciprocates. The reciprocation is maintained by a single compression spring in the cavity, and the length of the cavity, and compression of the spring, are adjustable to vary the cyclic firing rate. The firearm includes an especially simple trigger group arrangement. The lower receiver portion is structured to protect the trigger group. Also disclosed is an especially simple, yet practical ejector mechanism.

Abstract: A self-contained blowback-type firing unit insertable in a gun body as a discrete subassembly and including a barrel and bolt with a compression spring acting between them, characterized in that the barrel and bolt slide together on matching longitudinal track surfaces which are other than cylindrical and circumferentially complete, the bolt being slideable on no surfaces other than the barrel track surfaces.

Abstract: A foldable gun, useful in mob control and police undercover work because of small size and unassuming appearance when it is in folded configuration, includes a magazine housing and stock pivotally mounted to a receiver assembly in a manner in which the magazine housing may be pivoted to a parallel position adjacent a receiver assembly underside while containing a magazine. Pivotal mounting of the stock enables the stock to fold to an underside of the receiver assembly. A U-shaped configuration of the stock enables it to both contain and conceal the magazine housing and magazine when the gun is in the folded configuration. In this manner, an extremely compact folded gun is achieved, and further, the gun, when folded, does not resemble a weapon.

Abstract: The invention concerns an automatic, mass-obturated hand firearm comprising a body (1) with handle (2), a barrel (3) joined to the body, a breech block (4) with guide (5) constituted by the body and with cocking and firing mechanism (7), the guide of the breech block ascending rearward so that the rearward path of motion of the breech block deviates upward from the center-line (8) of the barrel. The purpose is to eliminate the problem of automatic hand firearms that during shooting the barrel tends to rise upwards.As taught by the invention, when the breech block (4) is in its forward position its center of gravity (9) is located forward of the handle (2). The breech block (4) is preferably disposed to have its major part forward of the rear end (10) of the barrel (3). Furthermore, the center of gravity (9) of the breech block (4) is preferably located forward of the rear end (10) of the barrel (3).

Abstract: A reversible front bolt for converting a firearm of a first caliber to fire cartridges of a second caliber; or to provide a second front bolt of the same caliber as a spare part. The regular bolt assembly comprises a front bolt, a plurality of rails and a rear bolt, wherein the rails connect, and rigidly position the front bolt with respect to the rear bolt. The front bolt has two firing faces, and to change from one firing face to the other, the rails are disconnected from the front bolt, the front bolt reversed and the rails reconnected to the front bolt.

Abstract: The submachine gun also has a forward housing. The forward housing is installed over the forward bolt and barrel, and rotatably secured to the assembly collar, and to the barrel by a sling swivel and a muzzle nut. The forward housing has integrally made there with a pistol grip and trigger housing. The trigger housing contains the trigger mechanism and sear, said sear when the submachine gun is assembled engages selectively the plurality of ring grooves around the forward bolt. Externally attached and mounted to the front housing is a sight bridge. Thus assembled, the front housing with pistol grip and sight bridge may be fully rotated 360.degree. with respect to the stock, magazine, and ejector port while the sear continously engages the ring grooves of the front bolt, and the weapon is ready to fire and fully operable at any point of the 360.degree. rotation.

Abstract: A conversion system for .30 caliber semi-automatic carbines permits selective use with .22 caliber ammunition. Modified barrel, bolt, operating slide and magazine sub-assemblies easily replace the corresponding original sub-assemblies to provide for direct blow-back operating slide actuation with .22 caliber ammunition. The replacement parts are of such simplified construction as permits manufacturing and sales as a conversion kit at a fraction of the original cost of the .30 caliber carbine to be converted. The conversion technique also provides for the independent manufacture of a unique .22 caliber semi-automatic carbine having the general appearance and "feel" of the standard .30 caliber M1 carbine.

Abstract: An automatic pistol with blowback action, in which a hammer is cocked by the recoil of a slidable breechblock, has a retaining member in the form of an elongate lid detachably secured to the gunstock for holding the breechblock in place, this lid carrying a backstop for a restoring spring tending to thrust the breechblock forwardly. The rear limiting position of the breechblock is defined by a pair of upstanding wings, rigid with the gunstock, against which two lateral shoulders of the breechblock come to rest upon manual arming or after the firing of a cartridge. A swingable control element on the breechblock, entrainable by a setting knob through a lost-motion coupling, has a blocking position in which it prevents the hammer from striking a firing pin lodged in the breechblock; in a working position, this element is movably interposed between the hammer and the firing pin to act as a force-transmitting device upon the release of the hammer by depression of the trigger.

Abstract: A stable automatic or semi-automatic firearm having a differential recoil system in which an open bolt has a designed mass and closing velocity to impact and drive a reciprocating barrel forwardly without rebound and remain locked to the barrel during the period when there is high firing pressure in the barrel. Since the bolt supports the cartridge during the time of high pressure, the cartridge is prevented from prematurely being extracted and rupturing; and since recoil momentum is utilized in arresting and returning the bolt, stability of the firearm is improved.