Abstract: A weapon system is provided. The weapon system includes a receiver and an operating group. The operating group includes a barrel extension at least partially housed within the receiver and arranged to axially translate relative to the receiver; an operating rod (op-rod) assembly arranged to axially translate within the barrel extension; and a bolt assembly arranged to axially translate within the barrel extension. The system further includes a gas accelerator coupled to the barrel and the op-rod assembly; a buffer assembly including a self-centering spring and a hydraulic piston assembly having a first end coupled to the receiver and a second end coupled to the barrel extension; and a feeder coupled to the receiver and configured to provide the round to the operating group.

Abstract: A bolt carrier for use with the AR15/M16 family of firearms is provided. The bolt carrier includes an integrally formed carrier key and spherical strike face surrounded by a cylindrical counterbore made with a downward angle to act against the tilting force imparted by the operating rod of the firearm's gas operating system. The outer surface of the carrier includes upper and lower running rails that all extend fully to the front face of the carrier to lengthen the carrier's rail support or bearing surfaces against the receiver. To improve the robust operation of the firearm in over the beach operations, the bottom and rear of the receiver extension has drain holes formed through which water is forced out of the receiver extension by the reciprocating action of the bolt carrier when the weapon is fired.

Abstract: In accordance with various exemplary embodiments, a firearm actuation system is provided. The firearm actuation system, comprising a housing, a guide, a contoured actuation handle, and a bolt. The system provides an actuation mechanism for an AR-15 which is engagable by a shooter where the AR-15 is in a shouldered firing position. The contoured actuation handle may be retained in the retaining slot to provide an action-open-position. The housing may also comprise a mounting rail with a plurality of grooves, where each groove may be configured with a unique indicator.

Abstract: An indirect gas operating system for a semi-automatic or automatic rifle is provided, the indirect gas operating system having: a gas block secured to the rifle; a barrel secured to the rifle; a bolt carrier slidably received within a receiver of the rifle; a means for moving the bolt carrier within the receiver using gases discharged into a bore of the barrel of the rifle, wherein the means for moving is removably secured to the gas block such that the means for moving can be removed from the rifle through a forward end of the gas block without removing the gas block from the rifle; and an externally threaded barrel nut for securing the barrel to the receiver.

Abstract: A reduced recoil weapon includes a housing and a receiver translatably disposed in the housing. A barrel is fixed to the receiver. A pair of recoil rods has first ends that are fixed to the receiver and are translatable with respect to the housing. Recoil springs are disposed around each recoil rod with first ends of the recoil springs abutting a forward surface of the housing. A bolt and bolt carrier are translatably disposed in the receiver. A bolt carrier return spring is disposed in the housing between the bolt carrier and a rear surface of the housing. Gas pressure from a gas piston on the barrel translates an operating rod toward the bolt carrier. An operating rod spring disposed in the receiver biases the operating rod toward the gas piston.

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: An automatic rifle bolt carrier with a fluted boss for the AR15/M16 family of firearms has been provided. The rear of the bolt carrier has been provided with a boss having bearing surfaces which are in operational contact with the interior of the host firearm's upper receiver to prevent the carrier from tilting while it is reciprocating during normal operation. The boss and rearward end of the bolt carrier are provided with flutes which allow water to flow between the buffer tube and upper receiver while the bolt carrier is reciprocating during normal operation, enabling a properly equipped firearm to be used during over the beach operations. The bolt carrier also includes a scallop cut located about the top of its backmost end which is perpendicular to the longitudinal axis of the bolt carrier.

Abstract: A rifle with an upper receiver and a barrel attached to the upper receiver and including a bolt carrier, and operating, buffer, and cooling systems. The operating system includes a cylinder and a piston coupled to receive propelling gases from the barrel. As the piston moves between retracted and extended positions the bolt carrier is moved between closed and open positions. The bolt carrier includes a weight movable within a guide frame between rearward and forward limits. The buffer system includes a compression spring in a tube attached to the upper receiver in abutting engagement with the bolt carrier. A partially fluid filled cylinder is attached to a coil of the spring and includes a piston and shaft. The piston is formed so that fluid in the cylinder restricts movement in one direction and allows free movement in a second direction.

Abstract: This application discloses a firearm gas system that includes a gas block that defines a gas port and a passage that receives a gas tube and an orifice plate that defines at least two orifices, where the orifice plate is positioned between a gas port in the barrel and the gas port on the gas block and where the orifice plate is movable with respect to the gas ports in the barrel and gas block to selectively position one of the orifices between the gas ports in the barrel and gas block where the orifices in the orifice plate have different orifice sizes.

Abstract: Embodiments of the present invention relate generally to cartridges and modifications for an M16/AR15 rifle. In one embodiment, a modified M16/AR15 rifle or carbine includes a bolt having a maximum outside diameter greater than that of a standard M16/AR15 bolt; and a bolt extractor pivoted to the bolt. The bolt and the bolt extractor are operable to: transport a cartridge from a magazine to a barrel, and eject a spent cartridge from the barrel. The rifle or carbine further includes a barrel extension configured to receive the bolt; a standard M16/AR15 upper receiver coupled to the barrel extension; a standard M16/AR15 lower receiver coupled to the upper receiver.

Abstract: A convertible gas piston conversion system for the AR-15, AR-10, or their variant rifle platforms is provided to convert the platform from a direct impingement gas system to a piston driven operating system. The conversion system includes a gas block having a barrel bore and two piston cylinder bores one on either side of the gas block. One of the piston cylinder bores is for utilization of the AR-15 rifle and the other of the piston cylinder bores is for utilization of the AR-10 rifle, making this piston system convertible for either the AR-15, AR-10, or any of their variant rifle platforms. A piston cylinder is inserted into the gas block via the piston cylinder bore and a piston is actuated inside the piston cylinder to cycle the rifle. A connecting link is coupled between the piston and an op-rod making the gas systems length adjustable by simply replacing the connecting link.

Abstract: A tactical firearm has an upper receiver defining a handguard mounting surface oriented in substantially normal relation with the bore of a rifle barrel and defining handguard mounting flanges that project radially from the upper receiver. A handguard is provided with like radiating handguard mounting flanges and is releasably secured to the upper receiver by fasteners. A barrel extends through the handguard and is secured by a barrel retainer to the upper receiver in a manner achieving clearance and thermal isolation of the handguard from the barrel and barrel retainer.

Abstract: An upper receiver assembly for a firearm having an upper receiver with an integral barrel nut, a handguard assembly and a barrel nut assembly with a barrel and lock nut is provided. The barrel is received by the upper receiver and is secured directly to the upper receiver using the lock nut. The upper receiver also includes an integral handguard mounting member to which the handguard assembly may be directly attached. The upper receiver assembly allows the user to attach both the barrel and handguard assemblies directly to the upper receiver, independently of one another.

Abstract: An improved bolt and bolt carrier with integral gas key having an extension nozzle threadedly secured and pinned to the gas key for use with a direct gas operated firearm is provided. The extension nozzle is designed to receive a portion of the host firearm's gas operating system. The firing pin retaining pin is oriented so as to expose its widest profile to the firing pin's annular flange, increasing its service life. The bolt has a plurality of lugs extending from its forward end. The extractor recess is constructed so that the face of the bolt is round and the adjacent lugs fully supported. The extractor engages approximately 17% more of a seated ammunition cartridge's rim as compared to the prior art AR15/M16 extractor. The result is an improved bolt and bolt carrier which provides for increased operational reliability.

Abstract: A tactical firearm having upper and lower receivers that are releasably connected. A cartridge gas energized bolt carrier assembly is moveable within the upper receiver and is provided with anti-tilt guidance with respect to a spring energized buffer mechanism, that is provided within a butt-stock of the lower receiver. The bolt carrier assembly moves a cartridge from a magazine and feeds the cartridge into the cartridge chamber of the barrel and returns the bolt carrier assembly to its closed and locked condition upon dissipation of the cartridge gas energizing force. The bolt carrier assembly is efficiently guided to prevent its misalignment during its rearward and forward auto-loading movement.

Abstract: A weapon system includes a receiver and an operating group with a barrel extension arranged to axially translate relative to the receiver. In the firing condition, the op-rod assembly and bolt assembly are driven by the drive spring such that the round is guided into the chamber and the op-rod assembly and bolt assembly are locked to the barrel extension and a forward momentum of the op-rod assembly is imparted to the operating group and the round is fired. A portion of an impulse stops the forward momentum of the operating group. In the recoil condition, the operating group is driven rearward by the remaining portion of the impulse, the gas accelerator imparts additional rearward momentum to the op-rod assembly and bolt assembly and stops rearward momentum of the barrel and barrel extension, and the op-rod assembly and the bolt assembly are stopped by the drive spring.

Abstract: A firearm having a gas piston system includes a bolt carrier, an adjustable gas piston block located forward on the firearm and an over-the-barrel spring and guide rod arrangement, all of which is housed and contained in a top rail that runs the length of the firearm and that maintains the alignment of these firearm components. The firearm also includes an ambidextrous, non-reciprocating charging handle located forward on the firearm and positioned within the top rail for charging the firearm.

Abstract: A firearm having a gas piston system includes a bolt carrier, an adjustable gas piston block located forward on the firearm and an over-the-barrel spring and guide rod arrangement, all of which is housed and contained in a top rail that runs the length of the firearm and that maintains the alignment of these firearm components. The firearm further includes components that provide full auto firing capability. These components include a specially designed auto bracket that cooperates with a modified bolt carrier and a modified upper receiver.

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 semi-automatic or automatic rifle comprising a barrel attached to and upper receiver and including a compressible bolt carrier extension system. The compressible bolt carrier extension system includes a bolt carrier, an extension spring, two pins, and a reciprocation bolt carrier extension piece. As a whole, the compressible bolt carrier extension system makes possible the use of elongated upper and lower receivers to be used for chambering long-action or other center fire cartridges for use with AR rifles such as the M-16, and M4 etc., eliminating the need for any buffer or buffer tubes other than those commercially available. A further advantage of the compressible bolt carrier extension system is the reduction of felt recoil as the system fully loads during the recoil stroke as it pushes against the buffer absorbing additional recoil energy. The system can be incorporated into firearms using a variety of cartridges.

Abstract: The embodiments described herein relate generally to a sleeve piston for operating the bolt carrier of a firearm. The sleeve piston can comprise a monolithic sleeve piston or it can comprise two or more sleeve-piston parts, thereby evenly distributing the reciprocating mass of an auto-loading firearm about its barrel, minimizing muzzle rise. The sleeve piston can further be coupled to the bolt carrier by two or more operating rods, thereby reducing the tipping force or off-axis torque experienced by the bolt carrier during firearm operation. The sleeve piston can also reciprocate in a sleeve gas block coupled to a barrel, thereby helping to transfer heat away from the barrel. The sleeve piston embodiments of the present invention provide a balanced and compact operating mechanism that is ideally suited for rifles, carbines, and personal-defense weapons.

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: A bolt carrier for use with the AR15/M16 family of firearms is provided. The bolt carrier includes an integrally formed carrier key and spherical strike face surrounded by a cylindrical counterbore made with a downward angle to act against the tilting force imparted by the operating rod of the firearm's gas operating system. The outer surface of the carrier includes upper and lower running rails that all extend fully to the front face of the carrier to lengthen the carrier's rail support or bearing surfaces against the receiver. To improve the robust operation of the firearm in over the beach operations, the bottom and rear of the receiver extension has drain holes formed through which water is forced out of the receiver extension by the reciprocating action of the bolt carrier when the weapon is fired.

Abstract: A multi use retro fit capable adjustable gas block designed to interface with an autoloading gas operated firearm is provided to replace existing gas blocks. The adjustable gas block optimizes gas flow into the host firearms operating system. The adjustable gas block has a spring loaded adjustment knob that releases when pulled forward allowing it to rotate. By rotating the adjustment knob the gas flow is increased or decreased based on one of four provided gas settings. Setting one is optimal for using a silencer, setting two is optimal for normal operations, setting three is optimal for adverse conditions, and setting four either turns the gas flow off optimizing sound reduction and providing for manual operation, or provides an extra high gas setting for the host firearm. The system works by precisely metering gas entering the operating system and not by exhausting excess gas into the atmosphere.

Abstract: An embodiment of a hand guard for a firearm, such as a rifle, includes an elongated tubular housing comprising an upper part, a lower part, opposite open ends, and a lumen configured to receive an intermediate portion of a barrel of a firearm longitudinally therein. An expansion collar is disposed at one end of the housing. The expansion collar has an expansion mechanism configured to adjustably compress the expansion collar and the lower part of the housing longitudinally between a pair of surfaces respectively disposed at opposite ends of the intermediate portion of the barrel.

Abstract: Weapons, weapon housing and methods of producing such weapons and weapon housings are disclosed. An example weapon housing for use with a firearm includes at least two housing shells. Each of the housing shells comprises at least one positioning recess. The example weapon housing also includes at least one connection block comprising connecting pins. On an assembly plane of the connection block, the housing shells are to be positioned and aligned on the connecting pins via the respective positioning recess to enable forces that are to act in or against a direction of fire to be absorbed by surfaces of at least one of the positioning recesses or one or more of the connecting pins.

Abstract: A method of operating a firearm having a modified gas operating system including directing gas from a barrel of a firearm upward through a barrel gas port, routing the gas from the barrel gas port through a gas jet, directing the gas from the gas jet through a gas operation tube, and directing the gas to a bolt carrier assembly to move at least a portion of the bolt carrier assembly relative to the barrel, the movement of the at least a portion of the bolt carrier assembly to cause excess gas in the barrel to be vented through the gas jet.

Abstract: A system for removably securing a hand guard to a semi-automatic or automatic rifle is provided. The system having: a first locking assembly for removably coupling a rear end of the hand guard to an upper receiver of the rifle; a second locking assembly for removably coupling a forward end of the hand guard to the rifle; and wherein the first locking assembly and the second locking assembly axially and rotationally position the hand guard with respect to the rifle and wherein the hand guard is not directly secured to a barrel of the rifle.

Abstract: An indirect gas operating system for a semi-automatic or automatic rifle is provided, the indirect gas operating system having: a sleeve removably secured to a forward end of a gas block of the rifle; a piston slidably received within the gas block, wherein the gas block and the sleeve fluidly couple the piston to a bore of a barrel of the rifle; wherein an increase in pressure in the bore of the rifle causes the piston to move away from the sleeve; and wherein the sleeve and the piston are each capable of being removed from the rifle through the forward end of the gas block.

Abstract: A firearm having a gas piston system includes a bolt carrier, an adjustable gas piston block located forward on the firearm and an over-the-barrel spring and guide rod arrangement, all of which is housed and contained in a top rail that runs the length of the firearm and that maintains the alignment of these firearm components. The firearm also includes an ambidextrous, non-reciprocating charging handle located forward on the firearm and positioned within the top rail for charging the firearm.

Abstract: A semi-automatic or automatic rifle. The rifle has a receiver having a receiver frame, a barrel removably connected to the receiver frame and a cover coupled to the barrel. A removable hand guard section extends over and generally surrounds the barrel, the removable hand guard section removably connected to the receiver. The removable hand guard section has a locating feature adapted to engage with the cover and locate the hand guard relative to the cover. The barrel has a locking collar adapted to removably position and lock the removable hand guard section relative to the receiver frame and the barrel. The removable hand guard floats in position relative to the barrel.

Abstract: A gas operating system for a firearm includes a gas block, a barrel nut that maintains the gas block at a predetermined axial position on a barrel of the firearm, a member that is movable with respect to the gas block axially with respect to the barrel in response to pressure exerted by expanding propellant gases conveyed thereto by the gas block and a mechanical linkage receiving a force form the member urging it in an axial direction of the barrel and coupled with a loading and ejection mechanism of the firearm to convey the force thereto for operating the loading and ejection mechanism. Various embodiments of gas block assemblies and operating rods for gas operating systems for firearms are provided.

Abstract: A gas operating system for a firearm renders the firearm capable of firing a wide range of shot loads by passively or automatically compensating for different shot loads. The firearm includes a plurality of ports formed in the firearm barrel, and corresponding ports formed in a gas cylinder of the gas operating system. The ports tap gases generated during firing which are used to cycle the firearm. When firing different cartridge loads, differing combinations of the ports are selectively at least partially blocked or otherwise obstructed by the cartridge casing according to the size of the cartridge.

Abstract: A firearm including a barrel having a breech and a muzzle defining a length of the barrel is disclosed. The firearm includes a hand guard having a first end and a second end with a front sight is attached to at least one of the barrel adjacent the muzzle and the second end of the hand guard. A housing is coupled to the front sight and defines a chamber having a piston disposed therein and movable between static and displaced positions. A receiver is coupled to the first end and a bolt carrier is disposed within the receiver and moveable between firing and rearward positions. A carrier key is attached to the bolt carrier and moves concurrently with the bolt carrier and a rod is permanently affixed to the carrier key and extends to a distal end with the piston engaging the distal end when moving to the displaced position.

Abstract: A bolt carrier for use with the ARI5/MI6 family of firearms is provided. The bolt carrier includes an integrally formed carrier key and spherical strike face surrounded by a cylindrical counterbore made with a downward angle to act against the tilting force imparted by the operating rod of the firearm's gas operating system. The outer surface of the carrier includes upper and lower running rails that all extend fully to the front face of the carrier to lengthen the carrier's rail support or bearing surfaces against the receiver.

Abstract: An indirect gas operating system for a semi-automatic or automatic rifle is provided, the indirect gas operating system having: a sleeve removably secured to a forward end of a gas block of the rifle; a piston slidably received within the gas block, wherein the gas block and the sleeve fluidly couple the piston to a bore of a barrel of the rifle; wherein an increase in pressure in the bore of the rifle causes the piston to move away from the sleeve; and wherein the sleeve and the piston are each capable of being removed from the rifle through the forward end of the gas block.

Abstract: A weapon system is provided. The weapon system includes a receiver and an operating group. The operating group includes a barrel extension at least partially housed within the receiver and arranged to axially translate relative to the receiver; an operating rod (op-rod) assembly arranged to axially translate within the barrel extension; and a bolt assembly arranged to axially translate within the barrel extension. The system further includes a gas accelerator coupled to the barrel and the op-rod assembly; a buffer assembly including a self-centering spring and a hydraulic piston assembly having a first end coupled to the receiver and a second end coupled to the barrel extension; and a feeder coupled to the receiver and configured to provide the round to the operating group.

Abstract: An automatic rifle bolt carrier with a fluted boss for the AR15/M16 family of firearms has been provided. The rear of the bolt carrier has been provided with a boss having bearing surfaces which are in operational contact with the interior of the host firearm's upper receiver to prevent the carrier from tilting while it is reciprocating during normal operation. The boss and rearward end of the bolt carrier are provided with flutes which allow water to flow between the buffer tube and upper receiver while the bolt carrier is reciprocating during normal operation, enabling a properly equipped firearm to be used during over the beach operations. The bolt carrier also includes a scallop cut located about the top of its backmost end which is perpendicular to the longitudinal axis of the bolt carrier.

Abstract: A recoil mechanism for an auto-loading firearm, having a gas-operated action bar assembly. One or more compression springs are used, mounted on associated retaining rods contained in a stationary orientation on the firearm. The springs are linked to the firearm's gas system at one end, and bear against stops affixed to ends of the spring retaining rods. The entire mechanism is contained within a forward grip mounted on the firearm, the grip optionally being provided with mounting rails.

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: A firearm action assembly having an action mechanism with an improved charging handle. The charging handle uses a rod member to engage the action for “cocking” the action mechanism. At an open end of the rod member is a handle which is secured to the edge of the action in a dormant state. Releasing of the lock is through the use of either of two finger members which are swivelly secured to each other. Pulling on either of these finger members operates the other which moves the other finger member.

Abstract: Improved receiver set for an indirect or direct gas operated firearm wherein the charging handle has been moved to the side of the upper receiver, the magazine well has been flared open to better receive a magazine, and the lower receiver has a semi-circular shelf in the rear which supports the proximal end of the bolt carrier as it is longitudinally displaced due to firing of the weapon.

Abstract: A charging handle for a firearm which can be used by either a right-handed or a left handed operator. The charging handle uses a rod member which engages the action of the firearm and is secured to the action via a locking mechanism. The locking mechanism is release when the handle is pulled by either the left hand or the right hand of the operator by pressing a first pressure surface when the left hand is used, and by pressing a second pressure surface when the right hand is used by the operator. This pressure forces the locking mechanism to disengage from the action mechanism.

Abstract: In accordance with various exemplary embodiments, a firearm actuation system is provided. The firearm actuation system, comprising a housing, a guide, a contoured actuation handle, and a bolt. The system provides an actuation mechanism for an AR-15 which is engagable by a shooter where the AR-15 is in a shouldered firing position. The contoured actuation handle may be retained in the retaining slot to provide an action-open-position. The housing may also comprise a mounting rail with a plurality of grooves, where each groove may be configured with a unique indicator.

Abstract: A rifle with an upper receiver and a barrel attached to the upper receiver and including a bolt carrier, and operating, buffer, and cooling systems. The operating system includes a cylinder and a piston coupled to receive propelling gases from the barrel. As the piston moves between retracted and extended positions the bolt carrier is moved between closed and open positions. The bolt carrier includes a weight movable within a guide frame between rearward and forward limits. The buffer system includes a compression spring in a tube attached to the upper receiver in abutting engagement with the bolt carrier. A partially fluid filled cylinder is attached to a coil of the spring and includes a piston and shaft. The piston is formed so that fluid in the cylinder restricts movement in one direction and allows free movement in a second direction.

Abstract: A gas operated autoloading firearm having an improved bolt carrier. The gas piston system may include a barrel defining a longitudinally-extending bullet pathway, a gas block defining a piston bore, a passageway fluidly connecting the bore with the bullet pathway for diverting combustion gas to the bore upon discharging the firearm, and a piston slidably disposed in the bore for reciprocating movement. The piston actuates a reciprocating bolt assembly including a bolt carrier slidably received in a receiver. The bolt carrier includes supporting and guiding surfaces configured to reduce receiver wear and bolt carrier drag.

Abstract: A rifle with an upper receiver and a barrel attached to the upper receiver and including a bolt carrier, and operating, buffer, and cooling systems. The operating system includes a cylinder and a piston coupled to receive propelling gases from the barrel. As the piston moves between retracted and extended positions the bolt carrier is moved between closed and open positions. The bolt carrier includes a weight movable within a guide frame between rearward and forward limits. The buffer system includes a compression spring in a tube attached to the upper receiver in abutting engagement with the bolt carrier. A partially fluid filled cylinder is attached to a coil of the spring and includes a piston and shaft. The piston is formed so that fluid in the cylinder restricts movement in one direction and allows free movement in a second direction.

Abstract: Improved receiver set for an indirect or direct gas operated firearm wherein the charging handle has been moved to the side of the upper receiver, the magazine well has been flared open to better receive a magazine, and the lower receiver has a semi-circular shelf in the rear which supports the proximal end of the bolt carrier as it is longitudinally displaced due to firing of the weapon.

Abstract: A gas piston retrofit assembly is provided for a firearm having a bolt assembly mounted within a receiver, a barrel extending forward from the receiver, and a front sight block mounted on the barrel. The retrofit assembly includes a gas tube extending into the front sight block fluidly connected with the barrel, a piston cylinder having an arcuate-shaped piston chamber fluidly connected to the gas tube, a piston including an arcuate-shaped piston head extending forward from a piston body and telescopically received in the piston chamber, and including a piston rod extending rearward from the piston body and dimensioned and configured to extend into the receiver for engaging with a bolt assembly within the receiver. Upon firing a round of ammunition, pressurized gas within the barrel enters the piston chamber to move the piston rearward, for cycling the bolt assembly. A method of using the same is also disclosed.

Abstract: This invention is about a firearm having an Articulated Bolt Train Assembly consisting of a series of linked carriages, containing mechanisms, displacing along non parallel tracks guides placed inside a by design Jaw Articulated Receiver that controls and governs its divergent paths, and holds all the sub assemblies in the convenient location allowing the synchronic movements of all the components to take place. The alternate divergent and converging motion of the Bolt Train Assembly and the Firing Mechanism, along, both, a bore axial path, and a transverse path, modifies the bearing of the recoil force, conveying a unique dynamic behavior, while performing different functions and achieving different purposes. In addition, the interaction of several components produce delay in the breech opening, and decelerate the rearwards motion to help, even more, the recoil damping. This invention has relevant consequences associated with the increased performance of firearms in civilian or military uses.