A system for connecting a barrel to an upper receiver of a modular rifle, the upper receiver having an upper receiver extension. The system comprises an upper receiver coupler having a first opening for receiving the upper receiver extension, which is removably secured in the first opening. The system includes a barrel coupler and a gas tube for attaching to a forward segment of the barrel, extending rearwardly along the barrel, passing through a second opening of the barrel coupler and coupled to a gas port that extends from the upper receiver and into the upper receiver coupler. The gas tube is shorter than the barrel. The barrel passes through and is removably secured within a third opening of the barrel coupler; passes through the first opening of the upper receiver coupler and into the upper receiver extension. The upper receiver coupler and the barrel coupler are removably connected.

A firearm gas redirection assembly directionally directs discharged gases from a barrel towards a bolt frame, and uses the energy from discharged gases to force a bolt rearwardly in an action. The barrel has an elongated body, an inner barrel sidewall, an outer barrel sidewall, a rear end, and a forward end. The forward end of barrel forms gas vents. The barrel is fixed motionless on the frame of the weapon. A jet nozzle concentrically couples around the barrel and integrates with a bolt frame. The jet nozzle has inner and outer jet sidewalls and a jet nozzle edge. The inner jet sidewall and outer barrel sidewall form a gas space that is in communication with the bolt frame. Discharge of firearm forces high velocity gas through gas vents that form in the barrel, through gas space, and finally against the jet nozzle edge. This forces bolt frame rearwardly.

The invention relates to a self-loading-pistol which comprises a frame (1), on which is slidably mounted a slide (11) for reciprocating movement, through the front part of which passes a barrel (9), which is fixedly and non-movably mounted on the frame (1), whereby a recoil spring (25) of the slide (11) is mounted on the guide (26) arranged under the barrel and a mechanism for locking the slide (11) during the firing process is arranged in the front portion of the frame (1) under the barrel (9). The mechanism for locking the slide during shooting comprises a two-armed lever (16) arranged swingingly on the axis (17), on whose front arm a locking member (14) is mounted in a seat (18) and on whose rear arm the damping member (15) is mounted in a seat (19), as well as a two-armed locking spring (21), pushing the locking member (14) and the damping member (15) upwards towards their seats (18 and 19), the locking member (14) and the damping member (15) being situated in the path of the motion of the support plate (13) of the slide (11). When the trigger is pulled rearwards for shooting, it causes a lever (37) to block any pivotal movement of the two-armed lever (16) and to retain it in place with its front arm and seat (18) in the uppermost position. When the trigger is in its forward rest position, however, the pivotal movement of the two-armed lever (16) is not blocked, so that during manual retraction of the slide the front arm of the two-armed lever (16) together with the locking member (14) in seat (18) can be brought out of the path of the motion of the support plate (13) with little or no effort.

The invention relates to a self-loading-pistol which comprises a frame (1), on which is slidably mounted a slide (11) for reciprocating movement, through the front part of which passes a barrel (9), which is fixedly and non-movably mounted on the frame (1), whereby a recoil spring (25) of the slide (11) is mounted on the guide (26) arranged under the barrel and a mechanism for locking the slide (11) during the firing process is arranged in the front portion of the frame (1) under the barrel (9). The mechanism for locking the slide during shooting comprises a two-armed lever (16) arranged swingingly on the axis (17), on whose front arm a locking member (14) is mounted in a seat (18) and on whose rear arm the damping member (15) is mounted in a seat (19), as well as a two-armed locking spring (21), pushing the locking member (14) and the damping member (15) upwards towards their seats (18 and 19), the locking member (14) and the damping member (15) being situated in the path of the motion of the support plate (13) of the slide (11). When the trigger is pulled rearwards for shooting, it causes a lever (37) to block any pivotal movement of the two-armed lever (16) and to retain it in place with its front arm and seat (18) in the uppermost position. When the trigger is in its forward rest position, however, the pivotal movement of the two-armed lever (16) is not blocked, so that during manual retraction of the slide the front arm of the two-armed lever (16) together with the locking member (14) in seat (18) can be brought out of the path of the motion of the support plate (13) with little or no effort.

A conversion unit for converting an AR-15 style military assault rifle to a submachine gun includes a central assembly having a magazine well and rear barrel mount. The magazine well can be inserted downwardly into the lower receiver of the assault rifle and accommodates magazines for shorter cartridges. The conversion unit also includes a forearm and barrel assembly and an upper receiver with a stabilizing rail. A pressure equalizing gas operating system eliminates the need for a buttstock with recoil spring. An operating rod extends forward from the upper receiver and into the forearm enclosure. The operating rod is attached to the bolt of the submachine gun and engaged with a reciprocating gas cylinder that surrounds the barrel.

A production AR-style semi-automatic rifle (i.e. AR-15, AR-10, M-16, M-4, etc.) that has been converted to a single shot rifle includes: a) conventional rifle components, including a receiving trigger, trigger guard, barrel; b) a semi-automatic firing mechanism including a gas actuated casing ejection and bolt reset mechanism including a bolt carrier with two carrier gas key threaded receiving orifices and having no production carrier gas key and a having a dual-bored metal block gas blocking restrictor mechanism attached to the bolt carrier and positioned so as to inhibit\semi-automatic operation of the AR-style semi-automatic rifle by disabling the automatic gas actuated casing ejection and automatic gas actuated bolt reset functionality. In some embodiments, there is a modified charge handle having an extension with two attachment orifices corresponding to the metal block gas blocking restrictor mechanism orifices and is coincidentally attached to the bolt carrier. There is also a method of converting a AR-style semi-automatic rifle to a single shot rifle.

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.

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.

A gas operated firearm includes a barrel with an integrally formed gas block as one piece with the barrel. A barrel nut is assembled over the integral barrel and gas block, securing the rear barrel end to a firearm receiver. Gas tube or piston assembly and field replacement are enhanced, along with accommodation of increased size barrels and integral muzzle end devices, no longer limited by internal dimensions of separately added gas blocks.

A gas operated firearm includes a barrel with an integrally formed gas block as one piece with the barrel. A barrel nut is assembled over the integral barrel and gas block, securing the rear barrel end to a firearm receiver. Gas tube or piston assembly and field replacement are enhanced, along with accommodation of increased size barrels and integral muzzle end devices, no longer limited by internal dimensions of separately added gas blocks.