Abstract: A firearm propulsion system for releasing a projectile from a firearm includes a firearm having a chamber, a barrel, and a firing pin with a primer. A supply port is passed through at least one of the barrel and the chamber so as to reach the interior. A control valve is in communication with the supply port and is configured to regulate the passage of pressurized gas into the at least one of the barrel and the chamber from the supply port. A sensor is included in the chamber and is configured to detect the location of the projectile passing through the chamber after firing the firearm. A control system communicates with the control valve and the sensor to selectively release pressurized gas into the chamber after firing.

Abstract: Cooling system of a gun canon tube by using water foggers and a jacket that concentrates this water around the outer surface of the canon tube.

Abstract: The present invention relates to a coupling for quick and easy attachment and detachment of a firearm accessory to a muzzle of a firearm, the coupling including a female member and a male member, where the female member is provided with a throughgoing bore and further is provided with a number of successive threaded portions and unthreaded portions around a circumference of the throughgoing bore, wherein the male member around an outer circumference is provided with the same number of successive threaded portions and unthreaded portions as the female member, the female member further being provided with a groove arranged around an outer circumference of the female member and a through-going slit extending from the groove to an end of the female member, the male member being provided with a number of recesses arranged around an outer circumference of the male member, a resilient lock element being arranged in the groove.

Abstract: A spin-stabilizing assembly is usable with a cylindrical barrel having a longitudinal center axis, a vertical center axis, and a distal end. The assembly includes a gimbal piece, a spinner cage, and a spinner body. A first end of the gimbal piece engages an outer diameter surface of the barrel proximate the distal end. The spinner cage is configured to engage a second end of the gimbal piece, and to pivot with respect thereto about the vertical center axis. The spinner body is disposed radially within the spinner cage and defines multiple axial vanes. The vanes, in response to impingement on the axial vanes of exhaust gases discharged from the distal end of the barrel, rotate the spinner body about the longitudinal center axis. Rotation results in impedance along the vertical center axis which minimizes vertical displacement or motion of the distal end.

Abstract: Methods and systems for limiting the sudden expansion of propellant gasses, products of combustion when firing a gun, exiting a barrel of a gun, which otherwise would result in a very loud noise, sharp “recoil” of the gun, and a pronounced “muzzle flash” if released unrestricted. By utilizing two or more completely segregated, or partially segregated, expansion chambers, the gasses can be allowed to sequentially expand and cool under tightly controlled conditions governed by the size and location of holes, or passageways, in the barrel which communicate with the interior of the expansion tube that encompasses the barrel. The expanding gasses are further controlled by the locations and volumes of each segregated expansion chamber, and holes in the structural vertical and horizontal bulkheads of the expansion tube, which can “steer” the gasses in order to achieve easy expansion as well as gas flow disruption goals by design.

Abstract: The disclosure of the present invention relates to a rifle barrel vibration dampener or to a vibration dampener sleeve configured to be fit over a portion of a rifle barrel in order to control the harmonic frequency vibration amplitude within the barrel, improving shot group accuracy; while additionally, improving the appearance of the rifle and protecting the outside surface of the rifle barrel.

Abstract: A device, comprising a first end cap having a bullet exiting aperture. The device includes a second end cap having an automatic-firing weapon barrel connector. The device includes a tubular sleeve having a main chamber through which a bullet passes, a first end coupled to the first end cap and a second end coupled to the second end cap. The tubular sleeve comprising an insulating liner layer of material configured for sustained temperatures of 1260° C. (2300° F.). The device suppresses sound of a muzzle blast as the bullet passes through the main chamber. A weapon system and method are also provided.

Abstract: Systems, methods, and apparatuses are described for accelerating projectiles at high velocity. A barrel may include one or more heaters configured to heat a bore of the barrel prior to launch of a projectile. The barrel bore may be formed in a tungsten sleeve and may be heated to high temperatures. Heat from the barrel bore may be transferred to expanding propellant behind a projectile as it travels through the barrel bore.

Abstract: A weapon barrel has a barrel core composed of iron or nickel alloy and at least one barrel jacket made from a metal-matrix material encasing the barrel core. The jacket and core thereby form a metal-metal-matrix composite barrel. The metal-matrix material may have a specific tensile strength that is greater than or equal to 80 N·m/g, and greater than or equal to the specific tensile strength of the barrels core material. The metal matrix material may include aluminum, titanium, beryllium and magnesium alloys, and composites, in addition to a filler material such as carbon nanotubes, graphite, diamond, carbides, and nitrides.

Abstract: A gun barrel with piecewise helical barrel fluting comprises a single start non-stop feature of alternating and intersecting right hand and left hand helical segments. Piecewise helical barrel fluting combines the ease of manufacture of a single start fluting with the improved performance benefits of a multi-start approach, namely increased barrel stiffness and resulting performance with respect to firing accuracy and firing precision.

Abstract: A sound suppressor for a firearm has one or more stacked baffles surrounded by an outer sleeve positioned such that an air gap exists between the baffles and the sleeve. The sleeve is connected to an outer portion of each of front and rear caps. The baffles are connected between the front and rear caps. The outer portions of the front and rear caps are disproportionately ventilated to induce directional air flow so as to facilitate heat dissipation.

Abstract: A heat shielding and thermal venting system, having a heat shielding element comprising an elongate, tubular member extending from a first end to a second end; a primary portion formed within a cavity of the heat shielding element; a secondary portion formed within the cavity of the heat shielding element, wherein the secondary portion has a reduced inner cross-sectional area when compared to an inner cross-sectional area of the primary portion; a plurality of entry apertures formed through the heat shielding element proximate the first end; a flare portion formed at the second end; and one or more restricted portions formed along the heat shielding element, wherein each restricted portion includes a reduced inner cross-sectional area, when compared to an inner cross-sectional area of an adjacent interior portion of the heat shielding element.

Abstract: Disclosed are examples of an apparatus for cooling a barrel 12 of a firearm 10 and examples of a cooled barrel assembly 32 for installation into an existing firearm 10. When assembled with the barrel 12, a contact surface 16 of a shell 14 is proximate to, and in thermal communication with, the outer surface of the barrel 18. The shell 14 is formed of commercially available or modified graphite foam.

Abstract: A weapon includes a cover system that extends a length. The cover system includes an opening that extends through the length of the cover system. The weapon includes a barrel that extends through the opening of the cover system. The cover system includes a composite material that is configured to provide thermal insulation relative to heat emitted from the barrel.

Abstract: A suppressor assembly for connection to the muzzle of a firearm includes an injector portion for connection to the muzzle and a suppressor portion for connection to the injector portion. The injector portion has a chamber for holding a quantity of fluid. When a firearm is discharged and the projectile passes through the injector portion, fluid is drawn from the chamber and into the suppressor portion to thereby shield the suppressor portion from full impact of gases associated with the fired projectile. The injector and suppressor portions can be operated independently and the injector portion can also function as a muzzle break, flash suppressor, and so on.

Abstract: A device and a method for performing thermal compensation of a weapon barrel of a gun having at least one weapon barrel which is mounted in a barrel cradle and in a barrel support as a prolongation of the barrel cradle. A plurality of temperature sensors are integrated into the barrel cradle and the barrel support and are connected via data lines to a data box. The data box is connected to a data processing device, which acts on actuators of the gun. The temperature at the barrel cradle and the barrel support is measured by temperature sensors. The temperature difference between upper and lower sides and right-hand and left-hand sides of the barrel cradle and the barrel support are determined. The barrel inclination is then calculated from these values, and the barrel inclination is then compensated by adjusting the orientation of the weapon barrel in its azimuth and/or elevation.

Abstract: A suppressor is disclosed for use with a weapon having a barrel through which a bullet is fired. The suppressor has an inner portion having a bore extending coaxially therethrough. The inner portion is adapted to be secured to a distal end of the barrel. A plurality of axial flow segments project radially from the inner portion and form axial flow paths through which expanding propellant gasses discharged from the barrel flow through. The axial flow segments have radially extending wall portions that define sections which may be filled with thermally conductive material, which in one example is a thermally conductive foam. The conductive foam helps to dissipate heat deposited within the suppressor during firing of the weapon.

Abstract: This invention is directed to a rifle barrel sleeve system for a gas operated weapon system comprising: a rear sleeve surrounding a rear portion of the rifle barrel; a front sleeve surrounding a front portion of the rifle barrel; a gas elbow support surrounding the rifle barrel disposed between the rear sleeve and the front sleeve having a gas chamber allowing gas to escape from a barrel gas port into the gas elbow; and, a void defined between the rear sleeve, front sleeve, gas elbow and barrel having filler material.

Abstract: A Seebeck active cooling device for use in conjunction with a weapon to cool the barrel, in order to reduce its weight, to remove the need for a second barrel, and to prolong its useful life. In particular, the cooling device employs a plurality of thermoelectric devices that convert the energy from the heat produced by the hot barrel during the operation to an electric current. The electric current powers a series of electric fans, which in turn, cool the barrel.

Abstract: A firearm cooling apparatus includes an apparatus housing having a housing interior; at least one vent opening in the apparatus housing and communicating with the housing interior; a fan in the housing interior adjacent to the at least one vent opening; a fan motor drivingly engaging the fan; a source of electrical current disposed in electrical communication with the fan motor; a switch disposed in electrical communication with the fan motor and the source of electrical current; a tubing connector rotatably carried by the apparatus housing; and an elongated, bendable, flexible and resilient cooling tube disposed in pneumatic communication with the housing interior through the tubing connector and having an air discharge end opposite the tubing connector.

Abstract: A firearm cooling device that includes a briefcase with a lockable lid, an adjustable firearm mount disposed upon the briefcase lid, an air pump disposed within a compartmentalized housing disposed within the briefcase, a rechargeable battery disposed within the compartmentalized housing, said battery in circuit with the air pump, an air vent disposed upon the briefcase in open communication with the air pump, an outlet port disposed upon the briefcase in open communication with the air pump, and an air hose releasably connectable to the outlet port, wherein an extant firearm is supportable within the adjustable firearm mount and air forcibly expelled by the air pump through the air hose is directable proximal the barrel of said firearm to more efficiently radiate heat therefrom whereby said firearm is more rapidly cooled thereby.

Abstract: A suppressor is disclosed for use with a weapon having a barrel through which a bullet is fired. The suppressor may have an inner portion having a bore extending coaxially there through. The inner portion is adapted to be secured to a distal end of the barrel. A plurality of axial flow segments project radially from the inner portion and form axial flow paths through which expanding propellant gasses discharged from the barrel flow through. The axial flow segments have radially extending wall portions that help to dissipate heat deposited within the suppressor during firing of the weapon.

Abstract: A weapon includes a cover system that extends a length. The cover system includes an opening that extends through the length of the cover system. The weapon includes a barrel that extends through the opening of the cover system. The cover system includes a composite material that is configured to provide thermal insulation relative to heat emitted from the barrel.

Abstract: A heatshield assembly for a metal barrel of a firearm includes a heatshield body provided with a rear end extending to a front end, and configured to overlie the barrel of the firearm. An insulating mounting arrangement is frictionally attached to and located within the heatshield body. The mounting arrangement is separate from the heatshield body for mounting the heatshield body to the barrel of a firearm in a continuous spaced relationship therefrom without damaging the barrel. With the heatshield body constructed of a metal material, the mounting arrangement is particularly constructed to prevent metal-to-metal contact between the heatshield body and the barrel.

Abstract: A suppressor assembly for connection to the muzzle of a firearm includes an injector portion for connection to the muzzle and a suppressor portion for connection to the injector portion. The injector portion has a chamber for holding a quantity of fluid. When a firearm is discharged and the projectile passes through the injector portion, fluid is drawn from the chamber and into the suppressor portion to thereby shield the suppressor portion from full impact of gases associated with the fired projectile. The injector and suppressor portions can be operated independently and the injector portion can also function as a muzzle break, flash suppressor, and so on.

Abstract: This invention is directed to a rifle barrel having a gas port for a gas operated weapon system comprising: an inner barrel; a gas redirection tube operably associated to the inner barrel so that expelled gas from a cartridge travels out of the gas port and into the gas redirection tube; a sleeve arranged around the inner rifle barrel defining a void between the rifle barrel and the sleeve surrounding the rifle barrel; and, filler material carried in the void defined between the inner barrel and the sleeve wherein the gas redirection tube is disposed within the filler material between the sleeve and the inner barrel.

Abstract: A thermal insulation jacket for a gun barrel, especially a cannon barrel, where the thermal insulation jacket includes a metal jacket that surrounds the gun barrel. In order to prevent uneven heating of the surface of the gun barrel within the thermal insulation jacket, an additional area that is especially effective at reflecting thermal radiation is provided on the inner surface of the metal jacket that lies opposite the underside of the gun barrel, so that when the gun barrel heats, the temperature differences between the upper side and the underside of the gun barrel are at least partially compensated. For this purpose, a reflective film is provided as the area that is a good reflector of thermal radiation. This reflective film is adhesively attached to the metal jacket.

Abstract: This invention is directed to a rifle barrel having a gas port for a gas operated weapon system comprising: a forward gas redirection tube operably associated to said rifle barrel so that expelled gas from a cartridge travels out of said gas port and into said forward gas redirection tube; a rear gas connector operably associated with said forward gas redirection tube for receiving expelled gas traveling in said forward gas redirection tube; a rear gas redirection tube removably connected to said rear gas connector for receiving expelled gas and transferring said gas to the action of the weapons system to assist with the cycling of the weapons system action; a sleeve arranged around said rifle barrel defining a void between said rifle barrel and said sleeve; and filler material carried in said void defined between said rifle barrel and said sleeve wherein said forward gas redirection tube is disposed within said filler material between said sleeve and said barrel.

Abstract: A barrel jacket covering at least partially the outer surface of the bullet-guiding barrel of a firearm is provided, wherein the barrel jacket has at least one inner casing and one outer casing and a spacer. The inner casing is arranged adjacent to the barrel, covering the barrel in a close-up position. The outer casing is arranged at a distance to the inner casing, covering the inner casing, thus providing a continuous gap. The continuous gap is stabilized by at least one spacer, which stabilizes the inner casing and outer casing in their relative positions.

Abstract: A firearm barrel having barrel flutes on the outer surface of the barrel where the barrel flutes are undercut relative to an outward radial vector from the center of the barrel at an arcuate radial distance that exceeds the arcuate radial distance of an undercut produced by a straight walled flute cutter such that the barrel flutes are hyper-undercut.

Abstract: A firearm having a receiver housing an action-cycling mechanism, a barrel having a muzzle opening on a distal end, a shroud coaxially surrounding at least a portion of the barrel, the shroud having a distal portion extending beyond the muzzle opening defining a shroud front region having a distal end portion, a proximal portion extending proximally from the muzzle opening defining an annular region between the barrel and shroud, a front wall disposed at the distal end portion of the shroud, the front wall having an opening to allow passage of a projectile fired from the gun barrel, a firewall disposed in the annular region of the proximal portion of the shroud, the firewall moveable relative to the gun barrel between a forward, at-rest position, and a rearward, compressed position, the firewall mechanically engaged with the action cycling mechanism, and heat-dissipating fins in the annular region extending longitudinally along, and radially outward from, the gun barrel to the shroud, the fins defining channel

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 thermal insulation jacket for a gun barrel, especially a cannon barrel, where the thermal insulation jacket includes a metal jacket that surrounds the gun barrel. In order to prevent uneven heating of the surface of the gun barrel within the thermal insulation jacket, an additional area that is especially effective at reflecting thermal radiation is provided on the inner surface of the metal jacket that lies opposite the underside of the gun barrel, so that when the gun barrel heats, the temperature differences between the upper side and the underside of the gun barrel are at least partially compensated. For this purpose, a reflective film is provided as the area that is a good reflector of thermal radiation. This reflective film is adhesively attached to the metal jacket.

Abstract: A firearm includes a support block having a forward end and a rearward end, and carrying a receiver on a top surface thereof. A rearward barrel guide having a thrust coupling extending radially outwardly therefrom, the thrust coupling engaging an engagement element located at the forward end of the support block, thereby aligning the rearward barrel guide with the support block. Also provided is a barrel having a breech end and a muzzle end, the breech end is received through the rearward barrel guide and coupled to the receiver. A forward barrel guide is fixed to the barrel intermediate the muzzle end and the breech end. A handguard assembly is received over the barrel and coupled to the rearward barrel guide and the forward barrel guide, stabilizing the barrel.

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 firearm barrel assembly having a gun barrel with a muzzle opening on a distal end, a shroud coaxially surrounding at least a portion of the barrel, the shroud having a distal portion extending beyond the muzzle opening defining a shroud front region having a distal end portion, a proximal portion extending proximally from the muzzle opening defining an annular region between the barrel and shroud, the shroud front region and annular region in fluid communication with substantially no obstruction between the shroud front region and the annular region, and a front wall disposed at the distal end portion of the shroud. The wall has an opening to allow passage of a projectile fired from the firearm.

Abstract: A modular fore-end rail assembly for a firearm is disclosed. The assembly includes an upper handguard having forward and rearward ends. A dovetail rail extends between the forward and rearward ends. Opposing sidewalls extend outwardly and downwardly from the dovetail rail, respectively. The sidewalls terminate in mounting channels. The rearward end includes a first clamping member. A clamp is removably secured to the rearward end and cooperates with the first clamping member to engage a barrel nut of a firearm. The clamp has an exterior surface including a slidable locking pin movable between a locked position and an unlocked position. A lower handguard includes sidewalls that extend outwardly and upwardly. The sidewalls terminate in mating formations that are configured to be slidably received in the mounting channels. A lock aperture is provided at a rearward end of the lower handguard.

Abstract: A firearm barrel assembly having a gun barrel with a muzzle opening on a distal end, a shroud coaxially surrounding at least a portion of the barrel, the shroud having a distal portion extending beyond the muzzle opening defining a shroud front region having a distal end portion, a proximal portion extending proximally from the muzzle opening defining an annular region between the barrel and shroud, the shroud front region and annular region in fluid communication with substantially no obstruction between the shroud front region and the annular region, and a front wall disposed at the distal end portion of the shroud. The wall has an opening to allow passage of a projectile fired from the firearm.

Abstract: A cooling system for a Gatling machine gun can be use to retrofit an existing machine gun or can be incorporated in a newly manufactured gun. The system directs fluid through the housing assembly of the machine gun to a location intermediate barrels of the gun, and discharges the fluid to cool the barrels.

Abstract: A firearm barrel assembly having a gun barrel with a muzzle opening on a distal end, a shroud coaxially surrounding at least a portion of the barrel, the shroud having a distal portion extending beyond the muzzle opening defining a shroud front region having a distal end portion, a proximal portion extending proximally from the muzzle opening defining an annular region between the barrel and shroud, the shroud front region and annular region in fluid communication with substantially no obstruction between the shroud front region and the annular region, and a front wall disposed at the distal end portion of the shroud. The wall has an opening to allow passage of a projectile fired from the firearm.

Abstract: A firearm barrel assembly having a gun barrel with a muzzle opening on a distal end, a shroud coaxially surrounding at least a portion of the barrel, the shroud having a distal portion extending beyond the muzzle opening defining a shroud front region having a distal end portion, a proximal portion extending proximally from the muzzle opening defining an annular region between the barrel and shroud, the shroud front region and annular region in fluid communication with substantially no obstruction between the shroud front region and the annular region, and a front wall disposed at the distal end portion of the shroud. The wall has an opening to allow passage of a projectile fired from the firearm.

Abstract: An evaporative barrel cooler for a firearm includes a firearm adapter having a mist nozzle, and a high pressure coolant reservoir attached to the firearm adapter with a flexible hose. The firearm adapter orients the nozzle inside a firearm chamber and aligned with the bore of a firearm barrel. The firearm adapter conforms to the interior of a firearm action and replaces a firearm bolt. The firearm adapter accesses the chamber through an open action port or through the bolt's raceway. The high pressure coolant reservoir may further include a hand pump attached to the reservoir for pressurizing the coolant. A coolant valve may be incorporated into the flexible hose to control the flow of coolant, whether it is water, alcohol, gunpowder or bullet metal solvent, or a nonflammable and nonreactive material.

Abstract: A barrel nut for coupling a barrel of a firearm to a receiver includes a body having a first end, an opposing second end, and an outer surface. A bore extends centrally through the body from the first end to the second end. A plurality of heat conducting fins extends radially outwardly from the outer surface of the body. A fastening element fastens the breach end of the barrel nut to the receiver.

Abstract: Cooling channels are milled on the peripheral surface of the individual cartridge chamber(s). Milling the cooling channels on the freely accessible surface makes it possible to simplify production.

Abstract: This invention relates to a fume extractor (10) for extracting fumes from a bore (12) of a barrel (14) of a gun and comprising an annular main reservoir (16); an annular inlet reservoir (18); and an annular auxiliary reservoir (20), all concentrically surrounding the barrel (14) and being in communication with each other and the bore (12). The inlet reservoir (18) is sandwiched between the main reservoir (16) and the barrel (14). The auxiliary reservoir (20) is sandwiched between the main reservoir (16) and the barrel (14) and is located adjacent the inlet reservoir (18) on a muzzle brake end thereof. The arrangement is such that the main reservoir (16) is pressurized when the gun is fired and such that the fumes in the bore (12) are extracted by the release of pressure in the main and auxiliary reservoirs (16) and (20), after the projectile has left the barrel (14).

Abstract: A hand guard assembly for a firearm including a barrel. The assembly includes a tubular unitary body mounted to surround a portion of the barrel substantially coaxially and in a transversely spaced relationship. The tubular body includes a plurality of air flow openings formed therethrough and at least one of a top rail formed as a unitary portion of the tubular body and extending rearwardly along an upper portion of a receiver of the firearm, side accessory rails formed as a unitary portion of the tubular body and on opposed sides of the tubular body, and a bottom accessory rail formed as a unitary portion of the tubular body and on a bottom surface of the tubular body. In the preferred method of fabricating the assembly, the body and any include accessory rails are extruded.

Abstract: A gun barrel handguard includes half sections having longitudinally spaced apart fins of plastic material positioned around the exterior of the gun barrel for absorbing heat but preventing it from being quickly transmitted to the exterior of the handguard.

Abstract: The present invention is a multi-piece barrel shroud which provides IR signature and radar backscatter reduction over the entire length of the barrel by utilization of special radar absorbing materials and shaped in accordance with commonly known radar signature reduction techniques. The interior of the shroud includes cooling passages for the circulation of ambient air by way of a forced air circulation system which provides IR reduction. To facilitate barrel movement while minimizing weight, the majority of the shroud is stationary and is independent of the gun barrel. At least one other piece of the shroud is attached to the barrel near the muzzle end and designed to move in unison with the muzzle during recoil. The recoiling portion of the shroud is sized to mate with an annular recess within the distal end of the stationary portion so as to provide continuous shielding of the barrel throughout the entire range of recoil displacement.

Abstract: The present invention is a multi-piece barrel shroud which provides IR signature and radar backscatter reduction over the entire length of the barrel by utilization of special radar absorbing materials and shaped in accordance with commonly known radar signature reduction techniques. The interior of the shroud includes cooling passages for the circulation of ambient air by way of a forced air circulation system which provides IR reduction. To facilitate barrel movement while minimizing weight, the majority of the shroud is stationary and is independent of the gun barrel. At least one other piece of the shroud is attached to the barrel near the muzzle end and designed to move in unison with the muzzle during recoil. The recoiling portion of the shroud is sized to mate with an annular recess within the distal end of the stationary portion so as to provide continuous shielding of the barrel throughout the entire range of recoil displacement.

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.