Abstract: A slide-action stock assembly for a semi-automatic firearm enables adjustment of the trigger pull length. An adjustable length interface interconnects a commercial off-the-shelf shoulder stock with a conjoined pistol grip and finger rest into a handle unit that slidably supports the firing unit portion of the firearm. The adjustable length interface includes a stem that is constrained to back-and-forth movement within a stem channel under the buffer tube. The stem includes a row of holes into which a plunger of the adjustable shoulder stock is set by the user to achieve a desired trigger pull length. A lock-out feature selectively impedes the slide-action mode. The finger rest can be positioned on either the right or left side of the pistol grip.

Abstract: An expandable linear explosive shape charge positioner for severing tubular members whereby a plurality of arc-shaped charge chambers are positioned along the same plane and adjacent to the interior walls of the tubular members and detonated to sever the tubular members. The invention is placed within a tubular member and includes a remotely extendible framework having remotely detonable linear explosive shape charges enclosed therein. When in the collapsed position, the apparatus passes through constrictions within the tubular members. When extended, the framework is positioned transversely to the axis of the tubular member with the shape charges positioned adjacent the interior walls thereof. Shape charge chambers with angled ends are presented to provide overlap when the device is fully extended to better ensure complete separation of the tubular member at the discontinuities of the shape charges about the plane of severance.

Abstract: Methods and structures for tightening the fit between upper and lower receiver subassemblies in a firearm comprising the addition of a raised embossment (projecting upward from the surface) on the upper side of a lower receiver walls or the underside of an upper receiver walls near the pivot pin. When the upper and lower receivers are connected by engaging the rear take-down pin the embossment leverages the receivers on the pivot pin to provide a tight fit.

Abstract: Tactical firearm systems and methods of manufacturing tactical firearm systems are discussed herein. In some embodiments, a tactical weapons platform can comprise a forend assembly adapted to house a portion of a barrel; a receiver assembly detachably coupled to the forend assembly and adapted to interface with a bolt action; and a butt stock assembly detachably coupled to the receiver assembly. In other embodiments, a modular stock assembly for a bolt action rifle can generally comprise a forend assembly, a receiver assembly, and a butt stock assembly. The forend assembly can have a body adapted to house a barrel in a free floating configuration, wherein the body surrounds at least a portion of the length of the barrel. The receiver assembly can be detachably coupled to the forend assembly and adapted to directly interface with a bolt action without bedding. The butt stock assembly can be detachably coupled the receiver assembly by a hinge.

Abstract: An angle-adjustable buffer tube system is a system that enables fluid transitions between a primary scope or sight and a backup offset iron sight without requiring the shooter to remove his or her cheek from the stock. The system includes a buffer tube and a firearm-mounting tube that is able to rotate concentric to the buffer tube. A stock may be mounted to the buffer tube while the firearm-mounting tube may be screwed into the body of a firearm. A lockable flange assembly featuring a flange, a mounting plate, a flange socket, and a plurality of grooves enables the rotation and additionally is able to lock the buffer tube and the firearm-mounting tube in place after the firearm has been rotated to a desired position. An annular retention plate is utilized to ensure that the buffer tube and the firearm-mounting tube do not separate from each other.

Abstract: A firearm with tilting barrel-receiver assembly. In one embodiment, the firearm includes a frame and a barrel-receiver assembly pivotably mounted to the frame. The barrel-receiver assembly is movable between an open position and a closed position. A latching mechanism may include a slide plate configured to selectively engage the frame. The latching mechanism is movable between a locked position wherein the barrel-receiver assembly is held in the closed position by the slide plate and an unlocked position wherein the barrel-receiver assembly is movable to the tilted open position. The slide plate may be spring biased into the locked position. An actuator button cooperates with the slide plate for moving the latching mechanism between the locked and unlocked positions.

Abstract: A convertible projectile launching device includes a projectile launching device, such as a paint ball marker, a less than lethal launcher or an airsoft gun, to which a user can secure at least one shell that changes the outer configuration or appearance of a projectile launching device on which it is secured into a MILSIM style projectile launching device. Any type of fasteners may be used to secure the shells to the device. The surface of at least one shell provides a rail system for mounting objects to the projectile launching device. The shell has a mating surface that engages a corresponding mating surface on the projectile launching device in order to increase stability of the shell. A blanking plug or a butt stock can be inserted into the rear of the shell, secured by a latch or other mechanism on at least one shell.

Abstract: The present disclosure provides an ergonomic handguard that supports rail mounted weapon accessories in a variety of different orientations. The handguard includes sides and bottom surfaces that are ergonomic. The stem includes modular sections of picatinny rail that can be attached to various locations on the handguard as needed to provide a mounting structure for rail based weapon accessories.

Abstract: A forend for use with a pump action firearm having a barrel with a magazine tube arranged adjacent and parallel thereto. The pump action firearm further includes an action slide assembly slidably receiving the magazine tube and the action slide assembly has a distal end and an action slide cap configured to engage the distal end of the action slide assembly. The forend comprises an elongate body having a U-shaped cross-section configured to be secured to the action slide assembly by an action slide cap engaged to a distal end of the action slide assembly. A guide defining a barrel receptacle is configured for keyed engagement to an interior of the elongate body to prevent rotational movement of the guide relative to the elongate body with the barrel receptacle facing toward the top of the U-shaped cross-section of the body. The barrel receptacle is configured to nest a radial portion of a barrel exterior, wherein the guide limits axial rotation of the forend about the magazine tube relative to the barrel.

Abstract: The present invention provides for a stock kit that converts a conventional rifle, such as an SKS, into bullpup configuration. The preferred embodiment of the provided stock kit does not require any permanent modification be made to the host firearm. The stock kit also provides for a rotatable handguard, trigger safety and a magazine release.

Abstract: A lower receiver for a firearm is disclosed that includes a trigger and hammer assemblies receiving section and a magazine well section, a raised bolt catch mount and a trigger access opening defined between the sections. The bolt catch mount includes an opening for insertion of a bolt catch mounting pin, a pin insertion relief formed at the magazine well section aligned with bolt catch mount opening. A trigger finger guide feature is defined between the trigger access opening and the magazine well section below the bolt catch mount.

Abstract: A firearm comprising a receiver including a threaded end with the receiver extending along an axis and a hand guard having an exterior surface and defining a hand guard bore along the axis with the exterior surface terminating at a mating surface disposed about the threaded end. The firearm additionally includes a barrel disposed within the hand guard bore and abutting the threaded end and a nut abutting the barrel and engaging the threaded end of the receiver to secure the barrel to the receiver. The firearm further including a securing device with the exterior surface of the hand guard defining an engagement area providing access into the hand guard bore and the securing device interfacing with the engagement area and extending into the hand guard bore to abut the nut and securely mount the mating surface of the hand guard to the receiver.

Abstract: A firearm having modular components that can be assembled under field conditions, by using simple tools. Upper and lower receivers are assembled by pins and a barrel and gas tube are secured to the upper receiver by a barrel nut. Mounting flanges of the upper receiver and a handguard are secured in reliable assembly by a manually actuated clamp mechanism having a clamping condition releasably securing the handguard to the upper receiver and having a releasing condition permitting separation of the handguard from the upper receiver. A pocketed soft protective container receives and protects the modular firearm components until firearm assembly takes place.

Abstract: A bolt action rifle with safety latching mechanism has an upper receiver including a movable bolt assembly, a lower receiver having a trigger assembly and releasably attached to the upper receiver, the bolt assembly movable between a cocked position and an uncooked position, and the upper receiver and the lower receiver including a latching mechanism operable to prevent the lower receiver from being detached from the upper receiver while the bolt assembly is in the cocked position.

Abstract: Firearms with barrel cinching clamps have a receiver having a forward portion defining an internally threaded bore, a barrel having a threaded end removably received in the bore, at least a selected portion of the forward portion being split by a gap, the selected portion having connection elements on opposite sides of the gap, and an adjustable element connected to the connection elements and operable to narrow the gap to secure the barrel in the bore and to widen the gap to permit the barrel to be readily unscrewed from the bore. The bore may define a bore axis, and the gap may be parallel to the bore axis. A circumferentially complete portion of the threaded bore including a plurality of threads adjacent to the gap may be unbroken by a gap. The circumferentially complete portion of the threaded bore may be forward and/or rearward of the selected portion.

Abstract: A stock bedding system for a firearm is disclosed. In one embodiment, the stock bedding system includes a stock having a pair of bearing surfaces that are configured and arranged to mutually engage a mating pair of bearing surfaces formed on the barrel-receiver assembly. At least one of the four bearing surfaces has a predetermined convex surface profile which causes the barrel-receiver assembly to roll in an angular direction away from one lateral side of the stock towards the opposite lateral side when the barrel-receiver assembly is mounted to the stock. The convex surface profile acts to tighten the engagement between the opposing bearing surfaces of the barrel-receiver assembly and stock providing a secure and vibration resistant mounting. In one embodiment, the convex-shaped bearing surface is defined by a pillar lug mounted in the stock which engages a mating substantially flat bearing surface formed on the barrel-receiver assembly.

Abstract: Weapon and gun accessories and grip devices and systems for attachment by adhesive or fasteners to various gun parts and components including gun rails.

Abstract: A quick-detach, free floating, two-piece forward hand guard assembly for a rifle, which includes an inner barrel nut adapted for connection to the rifle's receiver and an outer barrel nut telescopically received over the inner barrel nut and secured thereto to prevent rotation therebetween. The hand guard assembly also includes a top hand guard element engaged with and extending forwardly from the outer barrel nut in a laterally-stable cantilevered orientation above the rifle's barrel. A bottom hand guard element is matingly engaged with the top hand guard element for surrounding the bottom portion of the rifle's barrel and free-floats from the top hand guard element. A spring-loaded detent screw attaches the top and bottom hand guard elements together and also engages the inner barrel nut. For quick-detach barrel removal, the outer barrel nut may be hinged for clamshell action, with the inner barrel nut having a separable two-piece extension.

Abstract: The invention relates to a stock mounting device for fixing a stock on a receiver of a small arm that includes a clamping pin, and a clamping cam cooperating with the clamping pin, by which the shank can be mounted on the receiver by generating an axial force.

Abstract: The present invention describes a firearm hand guard assembly attachable to a firearm upper receiver and surrounding the firearm barrel distally along the longitudinal axis without touching the barrel. The hand guard assembly is comprised of an upper component and a lower component such that when the upper component and lower component are attached to one another with a firearm disposed therein, the sole contact between the firearm and the hand guard assembly is the contact between the firearm barrel nut and the inner surfaces of the proximal end of the hand guard assembly.

Abstract: A rifle having a receiver formed of upper and lower receiver portions attached to one another has one or more elastic bodies positioned between facing surfaces of the upper and lower receiver portions. The elastic bodies reduce play or lost motion between the upper and lower receiver portions for improved accuracy.

Abstract: A functional metallic and autonomous structure for fire-arms and revolvers is described. The revolver composed of metal/plastic, has a metallic structure, and is composed of the cylinder frame, provided with a hole having an internal thread for receiving and sustaining the revolver barrel. All the components of the discharge mechanism are embedded and/or sustained in said cylinder frame, defining the metallic structure, through which the junction of said cylinder frame, of the barrel and the components of the discharge mechanism will result in a semi-finished, fully functional revolver. The revolver also comprises at least a rear cover, a plate and a polymeric piece, intended for coating/covering at least a part of the metallic structure.

Abstract: The present disclosure provides an ergonomic handguard that supports rail mounted weapon accessories in a variety of different orientations. The handguard includes sides and bottom surfaces that are ergonomic. The stem includes modular sections of picatinny rail that can be attached to various locations on the handguard as needed to provide a mounting structure for rail based weapon accessories.

Abstract: A lower receiver assembly for a firearm is configured to be detachable coupled to a pistol grip and a feed ramp. The lower receiver assembly includes a lower receiver configured to accommodate an upper receiver, a barrel assembly and a magazine. The pistol grip is detachably coupled to the lower receiver. The lower receiver is configured to permit removal of the pistol grip for pistol grip maintenance or pistol grip replacement. The feed ramp is detachably coupled to the lower receiver. The lower receiver is configured to permit removal of the feed ramp for feed ramp maintenance or feed ramp replacement.

Abstract: Embodiments of the disclosure can include systems, methods, and apparatuses for installing a hand guard on a firearm. In some embodiments, a method of installing a hand guard on a firearm can be provided. The firearm includes a barrel, a barrel nut, and a delta ring. The delta ring is refracted away from the barrel nut. A number of hand guard members are positioned about the barrel. An annular groove formed between a forward plate and a rear plate associated with each hand guard member is mated with a portion of a flange of the barrel nut. The flange is secured within the annular groove of at least one hand guard member. The delta ring is advanced over a portion of some or all the hand guard members.

Abstract: A reciprocating sensory sighting system with a movable cheek weld member is translationally received by a firearm frame which defines a firing chamber and a passageway from an ammunition supply to the chamber. The cheek weld member includes a body, and a frame engagement portion extending therefrom. The frame engagement portion translationally couples to the frame, reciprocating between charging and firing positions to move an ammunition round from the supply, through the passageway, and to the firing chamber. The body has an exterior surface defining a cheek seat for shooter engagement when in the firing position, and an optional rear sight. A reciprocating sensory system, with or without the reciprocating sighting system, is provided with a sensory assisting element supported by the body. A firearm having such a reciprocating cheek weld member and/or a reciprocating sensory system, are also provided, along with a retrofit charging handle system for a firearm.

Abstract: The invention relates to a firearm and a component carrier therefor. The firearm has a barrel and a breech. The component carrier comprises a grip portion for receiving at least a portion of the barrel, a housing portion for receiving at least the breech, and a coupling member in a transition zone between said two portions for coupling the barrel with the breech. The grip portion is separated into a support part radially supporting the barrel, and a spacer part keeping the support part axially spaced from the coupling member. The spacer part is configured to receive the barrel with radial clearance.

Abstract: A forend for a firearm that includes a sight tunnel through the forend. The forend may be adapted to actuate a tube magazine of a shotgun to insert a shell from the tube magazine into a receiver of the shotgun. The forend may include an integral heat shield to protect a shooter from heat off of the barrel of the firearm. The forend may include a rail, such as an accessory rail, such as a Picatinny rail, that permits the attachment of an accessory to the top of the forend. The sight tunnel through the forend is below the accessory rail and permits the attachment of a light accessory to light up a front sight and/or a target. The front sight may be viewed through the sight tunnel by an operator of a firearm using the forend.

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: An apparatus for mounting accessories on a weapon mount. One embodiment of the apparatus includes an accessory interface system having a forward module coupled to a mounting module. The mounting module of the accessory interface system mounts on a weapon mount. The forward module of the accessory interface system provides a plurality of surfaces for mounting weapon accessories.

Abstract: Systems and methods for firearm receivers are described. Systems may include a receiver body, a tail; and a connection for coupling the receiver body to the tail. The receiver body and the tail may be made from different materials. A receiver system coupling apparatus may include one or more protrusions on a receiver body; and one or more one or more protrusions on a tail. The one or more protrusions on the receiver body may be coupled to the one or more protrusions on the tail to secure the receiver body to the tail. A method for producing a multiple component receiver system may include creating a receiver body from a first material; creating a tail from a second material; and coupling the receiver body to the tail with a connection.

Abstract: An adapter is described for use in attaching a shoulder stock to a handgun with a bottom opening handgrip recess. The adapter includes an upright member having upper and lower ends and a longitudinal slot to attach a stock. A lower arm extends forward from the upright member lower end, and a brace arm extends forward from the upright member upper end. A recess insert extends upwardly from the distal end of the lower arm. A latching member releasably secures the insert in the handgrip recess. Also described is a grip plate module to replace the grip plates on a handgun handgrip that does not include a recess. The module includes first and second replacement grip plates for attachment in place of the original grip plates, and a replacement grip plate connector extending between the replacement grip plates. The connector includes a bottom opening recess to receive an adapter insert.

Abstract: A rifle assembly includes a central chassis for carrying an action including a trigger and a trigger guard, the central chassis having a front portion and a rear portion, a rifle fore-end for carrying a barrel, the fore-end having a rear portion, and a fore-end adapter having a rear portion removably secured to the central chassis front portion and a front portion removably secured to the fore-end rear portion. The rifle assembly further includes a rifle butt stock having a front portion and a butt stock adapter having a rear portion removably secured to the butt stock front portion and a front portion removably secured to the central chassis front portion.

Abstract: A hand guard assembly for attachment to a firearm includes an anchor member and a sleeve. The anchor member is coupled to the firearm and defines an inner bore through which a barrel of the firearm extends when the anchor member is coupled to the firearm. The sleeve surrounds a portion of the barrel of the firearm in an overlying relationship. The sleeve is coupled to the anchor member at a first end so that when the assembly is attached to the firearm, the sleeve is cantilevered from the anchor member with an inner surface of the sleeve and an outer surface of the barrel being radially spaced apart from one another.

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: An adapter is described for use in attaching a shoulder stock to a handgun with a bottom opening handgrip recess. The adapter includes an upright member having upper and lower ends and a longitudinal slot to attach a stock. A lower arm extends forward from the upright member lower end, and a brace arm extends forward from the upright member upper end. A recess insert extends upwardly from the distal end of the lower arm. A latching member releasibly secures the insert in the handgrip recess. Also described is a grip plate module to replace the grip plates on a handgun handgrip that does not include a recess. The module includes first and second replacement grip plates for attachment in place of the original grip plates, and a replacement grip plate connector extending between the replacement grip plates. The connector includes a bottom opening recess to receive an adapter insert.

Abstract: A firearm receiver taking the form of a thixotropically molded magnesium alloy body. The receiver can be a lower receiver adapted for use in a modular rifle having both an upper receiver securable to a barrel and a lower receiver housing a trigger assembly. The receiver may also be nickel plated. Also disclosed is a method of manufacturing a firearm receiver that includes thixotropically molding the receiver out of a magnesium alloy. In some embodiments, the molded receiver defines substantially all openings and slots in the firearm receiver before conducting any post-molding processing steps on the receiver. The receiver may be nickel plated using an electroless nickel plating process. In some embodiments, the receiver has a surface roughness, Ra, that is between approximately 35 microinches and approximately 60 microinches. The receiver may be molded out of an AZ91D magnesium alloy.

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: The present invention relates to a mechanism for bedding a receiver frame (3) and/or a barrel (1) in a stock (2) of a firearm, the mechanism having a bearing component (8) which can be attached to the stock (2) and which, on its upper surface, has a bearing surface (10,11) for bearing the receiver frame (3) and/or the barrel (1). To ensure permanent and reproducibly accurate positioning, the lower surface of the bearing component (8) comprises a guide profile (9) for seating the bearing component (8) free from play in the stock (2).

Abstract: A barrel mounting and retention device for attaching a barrel to a receiver of a firearm. The barrel mounting and retention device can include a barrel extension disposed at a proximal end of the barrel, with an annular collar extending from the barrel extension and defining a first clamp face. A mounting plate having a second clamp face and defining a first axial bore fits over the barrel of the firearm with the barrel extending through the first axial bore. At least a portion of the second clamp face abuts a portion of the first clamp face as the mounting plate is secured to the barrel extension for mounting and retaining the barrel in communication with the receiver of the firearm.

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: Rifle upper receivers with integral magazine wells include an extruded elongate inverted U-shaped channel with an interior bore. The interior of the channel has elements formed as surfaces of extrusion. The surfaces of extrusion provide guidance and support for a magazine and trigger guard assembly pins. The present invention is manufactured by extruding an elongate tube in a closed-box profile with an interior bore, milling a series of slots into the top of the tube, machining a bottom channel opening by removing portions of the bottom of the tube, machining holes in the sides of the tube, and machining a recess in the top of the interior of the tube.

Abstract: An adjustable receiver cover for a firearm having an integral accessory mounting structure and pivotally attached to the firearm. A front mounting tab adjustably attached to the cover body accommodates physical variances between examples of said firearm. The front of adjustable cover is pivotally attached to the firearm by a pin. The adjustable cover is firmly affixed at its rear by a cam locking release button. The adjustable cover is self centering by means of an integral spring apparatus.

Abstract: Tip-off mounting device, wherein a base body has at least one recoil stud on its underside, which can engage in one of the slots of a Picatinny rail and is applied at the front in the firing direction and wherein the base body has at least one additional stop on its underside, which can engage in one of the slots of the Picatinny rail and is applied at the rear opposite to the firing direction.

Abstract: A handguard system for connecting an accessory to a firearm has a tubular body having a bore size to closely receive the body of the barrel nut. The tubular body has a tapered wedge portion that defines a gap therein. There may be a tapered clamp element adapted to fit over the wedge. The clamp element may be operable to squeeze the gap as the clamp element is pushed onto the wedge. The squeezing of the gap is operable to clamp the tubular body to the body of the barrel nut. The tubular body and the body of the barrel nut may each include a mating feature that prevents longitudinal movement of the tubular body while the mating features are engaged. The tubular body and the upper receiver may each include a mating feature that prevents rotational movement of the tubular body while the mating features are engaged.

Abstract: A shotgun includes a first barrel having a first barrel muzzle end and a second barrel having a second barrel muzzle end. The shotgun includes an expansion joint provided adjacent the first barrel muzzle end and the second barrel muzzle end to connect together the first barrel muzzle end to the second barrel muzzle end. The expansion joint is operative to allow movement of one of the first and second barrels relative to the other one of the first and second barrels to prevent bowing thereof.

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 locking device mountable to a rifle flash hider having grooved and flat portions. The locking device includes a body portion having an end, a bore and at least two undercut slots located in the end. At least two locking tabs are slidably engaged in the undercut slots, the locking tabs having a mounting hole and flat and arcuate confronting surfaces. An endcap is engageable with the body, the endcap having a central opening and at least two eccentric slots. At least two guide pins are located within the eccentric slots and engaged with the corresponding locking tab mounting holes. The locking tabs slidably move within the undercut slots in the body towards and away from the endcap opening when the endcap is rotated, thereby engaging and disengaging a flash hider having corresponding flat and arcuate portions.

Abstract: An improved barrel and attachment system for rapid fire weapons having a quick release and replacement. Further the barrel is lighter than comparable barrels for the same purpose, and has a flash suppression system.

Abstract: A handguard system for use on a rifle having a barrel and a receiver, the hand guard system includes a barrel nut having an inner surface with a threaded portion adapted to threadably engage the receiver for securing the barrel to the receiver and an outer surface, and a tubular handguard having an end. The tubular handguard is receivable about the barrel and is received about the barrel nut, engaging the outer surface thereof. REEXAMINATION RESULTS The questions raised in reexamination proceeding No. 90/008,357, filed Dec. 1, 2006, have been considered, and the results thereof are reflected in this reissue patent which constitutes the reexamination certificate required by 35 U.S.C. 307 as provided in 37 CFR 1.570(e) for ex parte reexaminations, or the reexamination certificate required by 35 U.S.C. 316 as provided in 37 CFR 1.997(e) for inter partes reexaminations.