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 replacement slide assembly for a pistol, the slide assembly having a barrel assembly with a barrel and a firing chamber. The barrel assembly also has a guide member which is a protrusion that extends horizontally outward from the barrel assembly. The replacement slide assembly also includes a housing with an interior wall that defines a groove that receives the guide member. The guide member and the groove in the housing are located forward of a firing pin assembly also mounted within the housing. The slide assembly or any firearm also includes an adjustable sight assembly that permits interchangeability between different types of sights without requiring that the firearm be re-sighted.

Abstract: A rifle kit comprises a rifle receiver structure having a central passage configured for having a substantially as-manufactured breech bolt of a pistol mounted therein and has one or more shoulder stock mounting portions configured for having a shoulder stock structure engaged therewith. A substantially as-manufactured breech bolt of the kit is configured by an original equipment manufacturer (OEM) thereof for being mounted on a pistol receiver body configured by the OEM. The rifle barrel is mountable within the central passage of the rifle receiver structure. A chamber end portion of the rifle barrel is configured for engaging a mating portion of the substantially as-manufactured breech bolt. A shoulder stock structure of the kit includes a receiver structure engaging portion configured for allowing the shoulder stock structure to be mounted on the rifle receiver structure exclusively through engagement with the one or more stock mounting portions of the rifle receiver structure.

Abstract: An automatic machine gun capable of being quickly reconfigured to fire different calibers of ammunition. The elements necessary to reconfigure the weapon are all stored and contained within the stock of the weapon. The reconfiguration process does not require any external tools.

Abstract: A firearm handguard assembly attachable to a receiver of a barrel of a firearm is disclosed. The firearm handguard assembly includes a barrel nut member, a locking sleeve member, a firearm handguard member and a plurality of fasteners. The locking sleeve member is disposed within an axial passage formed by the barrel nut member. A plurality of radial passages of the locking sleeve member are aligned with a plurality of radial passages of the barrel nut member. The firearm handguard member is arranged about the barrel nut member and the locking sleeve member such that the barrel nut member and the locking sleeve member are arranged within an axial passage of the firearm handguard member. The plurality of fasteners join the firearm handguard member to the barrel nut member and the locking sleeve member.

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 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: 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: Several improvements to the components and assembly method of a bolt-action firearm are disclosed. An improved bolt includes two separate members, which makes the bolt less expensive to manufacture while having a stronger extension handle. An improved takedown system and buttonless stop provide two easy ways to remove a bolt from a receiver when desired without misplacing any parts. An improved scope mount has a base connected to a receiver with two ends that substantially cover the top surface of the receiver and a middle portion that is narrowed over an opening to the receiver to accommodate a cartridge. A method of assembling a firearm involves providing a barrel with a threaded portion, fitting a crush washer over the threaded portion, inserting the threaded portion into a corresponding threaded portion of a receiver, and adjusting the barrel about the crush washer until a proper headspace is achieved.

Abstract: A quick-detach barrel mounting system for removing and attaching a barrel to a receiver of a firearm. The quick-detach barrel mounting system can include a barrel nut having a body defining an axial bore. A proximal end of the barrel is received at least partially through the axial bore, and the barrel nut releasably engages a front end of the receiver. A hand guard can be mounted to the receiver and can define a cutout proximate the receiver. The hand guard at least partially encloses at least a portion of the barrel and the barrel nut, and the cutout is at least partially aligned with the barrel nut. At least a portion of the barrel nut is accessible via the cutout of the hand guard for at least partially disengaging and engaging the barrel nut with the receiver when the hand guard is mounted on the receiver.

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: Firearms with integrated suppressors have a receiver having a forward portion defining an internal bore, a tubular body having sides defining an interior, a selected portion of the interior receiving a barrel, the barrel having a rear end removably received in the internal bore, a selected portion of the interior receiving a plurality of baffles, and wherein at least one side of the body can be disassembled into a panel to enable access to the baffles. Each of the baffles may define an aperture. The barrel may have a central bore that defines a bore axis, and the baffle apertures may be axially registered with the bore axis. At least one side of the body may have an attachment facility that removably connects an accessory to the rifle. The barrel, baffles, and body may be of monolithic or modular construction.

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 modular rifle includes an upper receiver assembly and a barrel assembly. The upper receiver, typically fashioned from aluminum, can be strengthened by insertion of a hardened metal liner insert inside the aft portion of the upper receiver. The upper receiver liner insert is secured within the aft portion of the upper receiver assembly by engaging screw threads on the liner insert with receiving threads inside the aft portion of the upper receiver and insertion of anchor pins into the aft portion of the upper receiver. The anchor pins impinge the liner insert such that it is prevented from rotating within the upper receiver. The barrel assembly is attached to the liner insert by engaging screw threads on the liner insert with threads within a barrel nut connector sleeve.

Abstract: A barrel nut for a firearm. A cylindrical shell is provided with internal threads extending from one end of the shell and opposite slots extending axially from the opposite end of the shell. A cylindrical core has external threads on one end, with the external threads being shaped to engage the internal threads of the shell. When the core is installed in the shell, it is secured at a desired axial location by at least one fastener secured in a bore of the shell and engaging one of a series of circumferential indentations in the core.

Abstract: A rifle conversion platform assembly comprised of components to fit around an existing action such that attachment locations such as a hand guard, pistol grip, and butt stock attachment locations are provided to have conventional rifle components, which in one form may be components of a high caliber semiautomatic rifle such as an AR-15, attached thereto.

Abstract: A quick-detach barrel mounting system for removing and attaching a barrel to a receiver of a firearm. The quick-detach barrel mounting system can include a barrel nut having a body defining an axial bore. A proximal end of the barrel is received at least partially through the axial bore, and the barrel nut releasably engages a front end of the receiver. A hand guard can be mounted to the receiver and can define a cutout proximate the receiver. The hand guard at least partially encloses at least a portion of the barrel and the barrel nut, and the cutout is at least partially aligned with the barrel nut. At least a portion of the barrel nut is accessible via the cutout of the hand guard for at least partially disengaging and engaging the barrel nut with the receiver when the hand guard is mounted on the receiver.

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: In embodiments, a modular rifle includes a lower receiver assembly, an upper receiver assembly housing a barrel, and a coupling mechanism. Upper receiver assembly has two portions, an aft portion and fore portion, commonly comprising a hand guard. The barrel is releasably attached to the upper receiver first portion by a hand-tightenable barrel nut sleeve connector. Upper receiver second portion is both releasably attached to the barrel nut connector sleeve and to the upper receiver first portion to prevent the barrel nut connector sleeve from rotating during firing of the rifle and to keep the second portion from detaching during firing of the rifle. Attachment of upper receiver second portion to the barrel nut connector sleeve is accomplished by a removable take-down pin and common screw clamp, which secure the barrel nut connector sleeve. Upper receiver first and second portions are connected by an attachment tab and receptacle.

Abstract: A firearm barrel nut assembly including a barrel nut, generally cylindrical in shape with a threaded central bore, and an externally threaded locknut which is used in conjunction with the barrel nut to secure a barrel to a firearm upper receiver. The barrel nut has an integral bushing on its exterior constructed to support either the gas tube or piston of the host firearm's operating system. The barrel nut is configured so that it may be independently and non-rotationally held within a vice or other fixture during installation of the barrel and while the locknut is tightened to a preset torque to hold the barrel in place while the barrel nut is independent of the torque applied to the locknut to properly secure the barrel to the upper receiver.

Abstract: A fixture for use with AR15/M16 type firearms is provided herein. The fixture is made up of several parts that when used in conjunction with one another mitigate the transfer of torque from the barrel nut to the firearms receiver during barrel installation. The fixture affords the user a method and apparatus that holds the barrel in alignment with the firearm receiver and secures the barrel against rotational movement during installation of a barrel nut or similar device. The fixture may be configured to work with the legacy AR15/M16 type barrel nut, as well as other designs as disclosed herein.

Abstract: A thermal barrier (1) for firearms (A) comprising a body (2), optionally substantially cylindrical, made of a ceramic material. The body (2) is shaped and configured for being placed between a respective barrel (C) of a firearm (A) and at least one structure (S) of the firearm (A). The body (2) of the thermal barrier (1) has a first portion (3) suitable for remaining facing the barrel (C) of the respective firearm (A), and a second portion (4) facing the side opposite with respect to the first portion (3), optionally suitable for bearing upon at least one portion of the structure (S) of the firearm (A).

Abstract: A firearm which is modifiable by the user such that a firearm barrel is arranged replaceable by the user, wherein the firearm comprises a barrel unit, which is detachable by the user and fastenable to a receiver, which barrel unit comprises the barrel and a locking piece, wherein the locking piece has a backward narrowing rear cone, which fits a cone in the receiver and which has a forward narrowing front cone, and which fits a cone in the centering bush, wherein to the centering bush is rotatably connected a clamping bush having an outer thread which fits an inner thread in the receiver, wherein by rotating the clamping bush in the locked direction, the rear end of the locking piece is centerable by means of the rear cone and lockable to the cone in the receiver.

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: Pistols and methods of manufacture are provided. A representative pistol includes a slide, at least part of the slide being made of plastic; wherein the pistol is a small caliber pistol or pistol for low-impulse ammunition or training pistol. A representative method for manufacturing a pistol includes: forming a slide of the pistol, with at least part of the slide being made of plastic; wherein the pistol is a small caliber pistol or pistol for low-impulse ammunition or training pistol.

Abstract: A firearm with a barrel fixed to a firearm body by at least one screw, wherein the firearm body includes a housing to receive the barrel and wherein the screw is fixed to the firearm body so that the firearm body tightens against or grips the outer surface of the barrel. In order to strengthen the connection between the barrel and the firearm body and fully ensure that the former does not move in either a longitudinal or rotary direction in relation to the latter, the barrel includes at least one surface hollow on its outer surface, and part of the screws already fixed to the firearm body are arranged inside a surface hollow, so that the screws inserted partly into the surface hollow provide longitudinal and rotary locking of the barrel against the firearm body.

Abstract: In embodiments, a modular rifle includes a lower receiver assembly, an upper receiver assembly housing a barrel, and a coupling mechanism. Upper receiver assembly has two portions, an aft portion and fore portion, commonly comprising a hand guard. The barrel is releasably attached to the upper receiver first portion by a hand-tightenable barrel nut sleeve connector. Upper receiver second portion is both releasably attached to the barrel nut connector sleeve and to the upper receiver first portion to prevent the barrel nut connector sleeve from rotating during firing of the rifle and to keep the second portion from detaching during firing of the rifle. Attachment of upper receiver second portion to the barrel nut connector sleeve is accomplished by a removable take-down pin and common screw clamp, which secure the barrel nut connector sleeve. Upper receiver first and second portions are connected by an attachment tab and receptacle.

Abstract: A firearm with barrel interlock system for a rotary mounted quick coupling barrel assembly. In one embodiment, the firearm includes a receiver and barrel assembly rotatably mounted thereto. A bolt carrier supporting a bolt is slidably disposed in the receiver and axially movable into and out of battery with the barrel assembly. The barrel interlock system may include a first barrel anti-rotation locking element disposed on the barrel assembly and a mating second barrel anti-rotation locking element disposed on the bolt carrier that is engageable with the first element. When mutually engaged, the first and second locking elements form a meshed relationship and prevent rotation and removal of the barrel assembly from the receiver. In some non-limiting embodiments, the locking elements may be in the form of a protrusion and complementary shaped recess.

Abstract: A spring-loaded quick coupling barrel retaining system for a firearm. The firearm includes a receiver, a barrel nut, and barrel assembly rotatably mounted thereto. In one embodiment, the barrel assembly may include barrel locking lugs which rotatably engage and interlock with corresponding locking elements disposed on the barrel nut such a splines. The barrel assembly further includes a spring member forming a flexible interface with the barrel nut. The spring member self-tensions and tightens the lockup between the barrel assembly and barrel nut to promote a tight fit. Some embodiments may include a lock nut and a setting tool for adjusting the spring force to promote consistently proper lockup from one replacement barrel assembly to the next.

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: A spring-loaded quick coupling barrel retaining system for a firearm. The firearm includes a receiver, a barrel nut, and barrel assembly rotatably mounted thereto. In one embodiment, the barrel assembly may include barrel locking lugs which rotatably engage and interlock with corresponding locking elements disposed on the barrel nut such a splines. The barrel assembly further includes a spring member forming a flexible interface with the barrel nut. The spring member self-tensions and tightens the lockup between the barrel assembly and barrel nut to promote a tight fit. Some embodiments may include a lock nut and a setting tool for adjusting the spring force to promote consistently proper lockup from one replacement barrel assembly to the next.

Abstract: An interchangeable barrel system and related method for a pistol includes a barrel insert having an anti-rotation protrusion and a receiver having a complementary configured socket configured for receiving the protrusion. An embodiment of a barrel insert includes a chamber for holding a cartridge and a locking mechanism configured for releasably securing the barrel insert to the receiver. In some embodiments, the locking mechanism comprises a threaded engagement between the barrel insert and receiver. The system allows barrel inserts of different calibers, configurations, and materials to be swapped with the receiver, and vice-versa.

Abstract: An automatic machine gun capable of being quickly reconfigured to fire different calibers of ammunition. The elements necessary to reconfigure the weapon are all stored and contained within the stock of the weapon. The reconfiguration process does not require any external tools.

Abstract: An initial velocity accelerating tube includes an outer pipe. Two ends of the outer pipe are connected with a stop member and a connection member, respectively. An inner pipe is provided in the outer pipe. Two ends of the inner pipe are inserted in the stop member and the connection member, respectively. When the initial velocity accelerating tube is mounted on a toy gun, one end of the inner pipe is against the front end of the barrel of the toy gun by the elastic force of the elastic member so as to tightly connect the barrel, providing an airtight effect. The barrel can be lengthened. To have a shoot with the long-barreled gun, the bullet can have a longer route to accelerate for getting a higher initial velocity.

Abstract: A modular fore-end rail assembly for mounting onto a firearm includes a hand guard and a bushing element that combines with an end portion of the hand guard to encircle the standard barrel nut, thereby supporting the entire assembly without requiring modification to the standard barrel nut. The thermal transfer characteristics of the material from which the bushing element is manufactured may be selected to either increase or decrease the rate at which heat is transferred from the barrel nut to the hand guard allowing for rapid changes of bushing elements and, therefore, rapid and selective changes in the heating rate of the hand guard.

Abstract: A multi-caliber firearm has a breech sleeve connecting a barrel to a receiver and a stock. The stock includes a forward V-block and a rearward V-block. Each of the V-blocks defines a V-cut along a top portion and a through hole substantially aligned with the cross-sectional center of the V-block. The forward V-block extends through a cutout portion of the receiver and into the breech sleeve. The breech sleeve is fastened to the stock through the through hole in the forward V-block to provide a rigid connection between the stock and the breech sleeve. The receiver is fastened to the stock through the through hole in the rearward V-block to provide a rigid connection between the receiver and the stock.

Abstract: A multi-caliber firearm has a breech sleeve connecting a barrel to a receiver and a stock. The stock includes a forward V-block and a rearward V-block. Each of the V-blocks defines a V-cut along a top portion and a through hole substantially aligned with the cross-sectional center of the V-block. The forward V-block extends through a cutout portion of the receiver and into the breech sleeve. The breech sleeve is fastened to the stock through the through hole in the forward V-block to provide a rigid connection between the stock and the breech sleeve. The receiver is fastened to the stock through the through hole in the rearward V-block to provide a rigid connection between the receiver and the stock.

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: The present invention relates to a changeover system for a hand gun comprising at least two different barrels, able to be applied exchangeably on a first grip piece of a weapon, for bullets of different caliber, and/or at least two different magazines for cartridges of different caliber able to be applied exchangeably on a first grip piece of a weapon. According to the invention, the changeover system comprises at least a second grip piece of the same weapon type, provided for a smaller caliber, on which at least one security arrangement against interchange is provided, which prevents the application of a barrel and/or of a magazine of a larger caliber on the grip piece provided for a smaller caliber. If required, the user of a second large-caliber weapon can then mount components of the small-caliber weapon onto the grip piece of the large-caliber weapon, in order to fire small-caliber ammunition therewith, for example for training purposes.

Abstract: Gun barrel for firearms made from a deformed material and method for producing the gun barrel material. The material has a chemical composition in % by weight of: Content C Si Mn P S Cr Mo Min 0.28 0.08 0.15 3.6 1.2 Max 0.36 0.26 0.35 0.005 0.002 4.4 1.8 Content Ni V W Ti As + Sn + Sb Fe Min 0.42 Rest Max <0.5 0.5? 0.15 0.08 0.007 and impurities due to smelting. The material has a hardness of at least 46 to 48 HRC.

Abstract: A reconfigurable toy gun includes a handle portion, a guide member coupled to the handle portion, and a barrel portion. The barrel portion is slidably coupled to the guide member and movable along the guide member between a first end portion of the guide member and second end portion of the guide member.

Abstract: Systems and methods for using a cartridge case as a tool to install or remove firearm barrel attachments. The barrel attachment includes a channel for engaging a cartridge case rim. This rim channel provides mechanical leverage for rotating the barrel attachment around a bore axis of the firearm barrel. The rim channel may include a curved portion to increase the load-bearing contact area. The contact area between the rim of the cartridge case and the barrel attachment can be further increased by a half-moon insert.

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: 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 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 modular fore-end rail assembly for mounting onto a firearm includes an upper hand guard, a lower hand guard and a clamping member that combines with the rear portion of the upper hand guard to encircle and clamp onto the barrel nut thereby supporting the entire assembly from the front of the upper receiver and preventing any transfer of load into the barrel. The lower portion of the hand guard is slidably received into channels formed in the upper hand guard and is retained in its installed position by a spring biased detent located in the clamping member. The lower hand guard is removable by simply depressing the detent and sliding the lower hand guard forward. By providing for the easy removal of the lower hand guard, other auxiliary devices may be mounted to the upper hand guard.

Abstract: A firearm with barrel interlock system for a rotary mounted quick coupling barrel assembly. In one embodiment, the firearm includes a receiver and barrel assembly rotatably mounted thereto. A bolt carrier supporting a bolt is slidably disposed in the receiver and axially movable into and out of battery with the barrel assembly. The barrel interlock system may include a first barrel anti-rotation locking element disposed on the barrel assembly and a mating second barrel anti-rotation locking element disposed on the bolt carrier that is engageable with the first element. When mutually engaged, the first and second locking elements form a meshed relationship and prevent rotation and removal of the barrel assembly from the receiver. In some non-limiting embodiments, the locking elements may be in the form of a protrusion and complementary shaped recess.

Abstract: A barrel retaining system for a firearm includes a firearm receiver having a barrel nut coupled thereto and a barrel assembly, which in one embodiment may include a barrel with a barrel extension coupled thereto. The barrel extension includes a plurality of barrel locking lugs that rotatably engage corresponding locking elements disposed on the barrel nut. The barrel extension may further include a flange that may engage one end of the locking elements of the barrel nut and the barrel locking lugs may engage an opposite end of the locking elements to wedge the locking elements therebetween for securing the barrel extension to the barrel nut. The firearm may be an autoloading rifle in some embodiments.

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.