Abstract: A firearm barrel having an inner layer and a shroud. The inner layer surrounds a concentric bore and has an outer diameter. The inner layer is made up of an unperforated core that directly surrounds the concentric bore and a perforated core that surrounds the unperforated core. The shroud surrounds the perforated core, which is made up of a plurality of equilateral triangular cutouts and a plurality of circular cutouts in a grid pattern that is configured to form structural ribs between the unperforated core and the outer diameter of the inner layer. The inner layer is preferably made of steel, and the shroud is a cylindrical titanium tube.

Abstract: The present invention relates to an arrangement for aligning a sub-calibre barrel (1) for use in a principal weapon barrel comprising i) an insert (4) arranged in said principal weapon barrel ii) front securing means (8) for aligning the sub-calibre barrel (1) iii) rear securing means for securing the rear end of the sub-calibre barrel (1), wherein iii.a) said rear securing means comprise a barrel nut (2) in which said sub-calibre barrel (1) is inserted; iii.b) clamping means (3a, 3b) securing said barrel nut (2) to said insert (4) and said clamping means (3a, 3b) in said principal weapon barrel. The invention also relates to a training weapon comprising the arrangement and a method of aligning the training weapon.

Abstract: A shooting rest and associated methods. The shooting rest includes a forward support and a rear support both supported by a frame. The forward support is configured to clamp a forward portion of the firearm and permit rotation of the firearm with respect to the frame about a pitch axis to adjust a vertical aim of the firearm and about a yaw axis to adjust a horizontal aim of the firearm. The rear support includes a platform positioned to support a bottom of a trigger hand grip portion of the firearm. The platform is adjustable in elevation to adjust the vertical aim of the firearm.

Abstract: Disclosed is an autoloading shotgun firearm which shares interchangeable fully compatible modular sub-assemblies, ergonomics, parts commonality, and exterior appearance with the AR rifle platform. Rapidly reversible tool less conversion from rifle to shotgun and vice versa is accomplished by substitution of the AR rifle upper receiver and ammunition detachable magazine with fully compatible shotgun upper receiver and ammunition detachable magazine. Said shotgun utilizes standard rimmed shotgun ammunition via features in the detachable magazine which securely maintain the position and facilitate the feeding of the cartridges during normal operation. No alteration of the AR rifle lower receiver is required. A short-recoil action is integrated into the shotgun upper receiver. The external appearance and functionality of the AR rifle are retained while eliminating the complexity and inherent fouling issues of typical gas systems used in the AR rifle.

Abstract: Embodiments disclosed herein describe systems and methods for simulating realistically practicing firing of a firearm. More particularly, embodiments disclose coupling a moving cylinder with a thrust rod into the barrel of a firearm, wherein responsive to a user pressing the trigger, the thrust rod moves a slide of the firearm.

Abstract: An apparatus for designing a rifling rate to increase a lifespan of a gun barrel includes: a node selection module selecting and distributing the predetermined number of node points according to preset constraints between preselected starting and end rifling angles; a sorting module sorting distributed node points; and a profile generation module calculating a rifling rate curve using sorted node points, and generating a rifling rate profile using the rifling rate curve.

Abstract: The invention relates to a firearm comprising a housing (1), having a cartridge feed (2), a breechblock, an impacting unit having a trigger, optionally a magazine shaft (3) for holding a magazine (4), and a unit (5) of two barrels (6, 7) arranged one over the other. The upper barrel (6) is longer than the lower barrel (7). Guide protrusions (8) are provided on the unit (5) of the two barrels (6, 7), which guide protrusions are guided in corresponding control tracks (9, 10) in the housing (1), whereby the two barrels (6, 7) can be moved along the control tracks (9, 10) between two end positions, wherein, when each end position is reached, alternately one of the two barrels (6, 7) aligns with the cartridge feed (2) and therefore forms the active barrel, which can be locked in this position.

Abstract: Disclosed is an autoloading shotgun firearm which shares interchangeable fully compatible modular sub-assemblies, ergonomics, parts commonality, and exterior appearance with the AR rifle platform. Rapidly reversible tool less conversion from rifle to shotgun and vice versa is accomplished by substitution of the AR rifle upper receiver and ammunition detachable magazine with fully compatible shotgun upper receiver and ammunition detachable magazine. Said shotgun utilizes standard rimmed shotgun ammunition via features in the detachable magazine which securely maintain the position and facilitate the feeding of the cartridges during normal operation. No alteration of the AR rifle lower receiver is required. A short-recoil action is integrated into the shotgun upper receiver. The external appearance and functionality of the AR rifle are retained while eliminating the complexity and inherent fouling issues of typical gas systems used in the AR rifle.

Abstract: A system for reducing an extraction force required for removing a spent munition cartridge case from a weapon after firing, the system including a chamber; and a plurality of movable components in the chamber that are configured to radially expand with a corresponding expansion of a fired munition cartridge case, wherein radial expansion of the plurality of movable components causes a rearward force on the plurality of movable components and the spent munition cartridge case. The chamber may include a tapered wall, and the plurality of movable components may matingly align with the tapered wall. The plurality of movable components may align with one another. Each movable component may include a tapered outer surface comprising an angle greater than an angle of an outer surface of a pre-fired cartridge case.

Abstract: A device incorporates a light source, a power source, and a control unit. The device has two operating modes and a switch to select one of the two modes. In a first operating mode the light source has a first control function wherein it emits light and a second control function wherein it does not emit light. In a second mode the light source emits light when the sound of a gun firing pin is detected.

Abstract: The invention relates to the firearm hardware, namely to barrel coupling for firearm. Due to the new muzzle adapter construction, clamping mechanism, which consists of a separator with cams and a clamping sleeve, it makes it possible to mount muzzle accessories to the barrels without any special preparation. The separator is manufactured as a casing with a plurality of cam sockets and a plurality of elongated L-shaped cams insertable into the said sockets with the longer part of the cam shaped to match the socket. The new barrel coupling is more reliable and more durable, it is comfortable and easy to install and remove.

Abstract: A modular automatic or semiautomatic rifle. The rifle has a lower receiver assembly having a fire control assembly for firing the rifle. An upper receiver assembly is provided with a frame and a bolt carrier assembly configured for firing bullets of a predetermined caliber. The lower receiver has a mating interface configured for operably joining the lower receiver assembly to the upper receiver assembly, and for operably joining the lower receiver assembly to another upper receiver assembly different from the upper receiver assembly configured for firing bullets of the predetermined caliber. The other upper receiver assembly has a different frame and different bolt carrier assembly configured for firing bullets of a different predetermined caliber.

Abstract: A revolver has a shroud for housing a barrel. The shroud has a receptacle formed on an upper surface. The receptacle is aligned with one sight receiving flat on an exterior periphery of the barrel. The flat is located adjacent to the muzzle end of the barrel. A front sight is disposed within the receptacle. A bottom portion of the sight is in registration with the flat so as to prevent rotation of the barrel.

Abstract: This invention is a precision weapon that utilizes solely as a projectile, a precision-ball made out of a suitable material namely solid C260 brass. It employs a smoothbore precision-barrel with a metal toothed rack/rail affixed along the northern hemisphere of the muzzle of the barrel that effectively converts some of the forward motion of the ball into rotational motion so that the ball is mechanically forced to rotate upwards/backwards at very high speed that can run into millions of rotations per minute, vastly improving its ballistic coefficient and downrange accuracy. The weapon can be produced in a variety of existing types of firearms such as bolt-action, falling-block or semi-automatic, and can be chambered for a variety of calibers. A 5.5625 mm caliber bolt-action rim fire weapon for instance will provide a user with a weapon ideal for hunting small-game or for target shooting purposes. See FIGS. 1, 2 and 3.

Abstract: An accessory is mountable to the side plate of a gun. The accessory may be a sighting device including a light source (preferably a laser), and a power source connectable to the light source. The side plate is positioned on the gun, which is preferably a revolver, preferably by being screwed to it. The side plate includes an attachment mechanism that is preferably located behind the trigger guard and behind the gun cylinder, wherein the accessory is attachable to the attachment mechanism.

Abstract: A maneuver cartridge device for use in a self-loading firearm includes a barrel extending from a chamber to a muzzle side and having an intercepting device arranged on the muzzle side for intercepting a projectile. The barrel has a first barrel section that adjoins the chamber and a second barrel section that adjoins the first barrel section. The first barrel section has a first cross section corresponding to a caliber of the projectile and the second barrel section has a second cross section that is larger than the first cross section.

Abstract: An insertion tube (1) for firing sub-caliber ammunition bodies (20) using a high caliber weapon (10) is inserted into the loading chamber (11) of the weapon (10). The tube wall (2) of the insertion tube (1) has penetrating recesses (3) for compensating pressure differences between the inside of the insertion tube (1) and the loading chamber (11). A weapon includes an insertion tube (1) which can be inserted into the loading chamber (11) of the weapon (10) for firing a sub-caliber ammunition body (20), the insertion tube (1) being designed in the above-described manner.

Abstract: A firearm for implementing an improved 9 mm cartridge is provided, wherein the improved 9 mm cartridge includes a 9 mm bullet associated with a 45-9 cartridge casing, wherein the 9 mm bullet weights at least 90 grains and wherein the 45-9 cartridge casing is configured to contain a propellant sufficient to propel the 9 mm bullet to a velocity of at least 1600 feet per second. The firearm may include a barrel, wherein the barrel is configured to operably interact with the 9 mm bullet and a chamber, wherein the chamber includes at least one chamber portion sized and shaped to operably associate with the 45-9 cartridge casing and a free-bore, wherein the free-bore includes at least one free-bore portion sized and shaped to operably associate with the 9 mm bullet.

Abstract: A composite gun barrel comprising: an inner rifled liner tube having an outer surface; and an outer sleeve made from a shape memory alloy and having an inner surface for disposition against the outer surface of the inner rifled liner tube; wherein the inner rifled liner tube is configured for guiding projectiles and the outer sleeve is configured for dampening the firing vibrations encountered by the inner rifled liner tube.

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: An interchangeable, modular firearm muzzle mountable system can include a first firearm muzzle mountable device and a second firearm muzzle mountable device. Each device can have an inlet end coupling feature proximate to an inlet end of a central chamber and an outlet end coupling feature proximate to an outlet of the central chamber. The central chamber can be oriented along a central axis within an outer shell and the inlet and the outlet can be configured to allow a projectile from a firearm to pass along the central axis. The inlet end coupling feature of the first device can be removably coupleable with a muzzle end of a firearm and the inlet end coupling feature of the second device can be removably coupleable with the outlet end coupling feature of the first device beyond the muzzle end of the firearm.

Abstract: The present invention relates to an extension barrel, which comprises an outer tube and a dye coating module. The outer tube is provided at the rear end thereof with a connector portion adapted for connection to a front end of a pneumatic gun. The dye coating module is mounted within the outer tube, so that a bullet projected from the pneumatic gun is coated with dye having a desired color when passing through the dye coating module. As a result, the object hit by the bullet is stained with the color and can be easily identified.

Abstract: The present invention relates to barrel extensions for firearms that have been converted to fire different, most likely lower, caliber ammunition than the firearms were originally designed to accommodate. The present invention in several embodiments is a barrel extension designed to supplement or replace the barrels and/or barrel extensions of firearms that have a sub-caliber conversion installed. Several embodiments of the present invention are configured to be installed on AR15 family rifles with a .22LR ammunition conversion to allow for accurate shooting of the .22LR ammunition through the barrel extension.

Abstract: The present invention teaches an insert locking mechanism incorporated into a sub caliber action device, installable within an upper receiver of an AR-15 type firearm, and which interfaces with an upper receiver mounted forward assist for use with such as .22 caliber ammunition and in order to eliminate movement or play of the chamber insert adaptor associated with the substituted sub caliber action. The mechanism includes a generally cylindrical shaped body supported upon the action and exhibiting a plurality of radially projecting and circumferentially extending lugs which are configured to mate and seat within a plurality of grooves circumferentially arrayed within a barrel defined in the upper receiver.

Abstract: A firearm with a barrel that uses an ammunition discharge chamber that includes improved throat located between the chamber's free bore and the rifle bore. The improved throat includes a relatively short, inward aligned first step, an intermediate elongated cylindrical body, and a longer, inward aligned second tapered step. Formed on the inside surfaces of the first step, the elongated body and the second step are rifling grooves and lands that gradually their depths and heights from rear to front direction. The two steps are tapered inward between 1.0 to 1.5 degrees. Using a short first step, an elongated cylindrical body with straight sidewalls, a longer second step with continuous grooves and lands that begin gradually in depth and height from rear to front directions, chamber pressure is reduced thereby enabling more gun powder to be used and bullet misalignment in the rifle bore is reduced.

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: A duplex weapon system that is capable of firing a high-mass/low-velocity (“HMLV”) projectile followed by a conventional projectile such as a bullet. A barrel adapter is aligned with the bore of the barrel of a conventional firearm. The barrel adapter includes an adapter bore running completely through its length, with the adapter bore terminating in an exit in the forward portion of the barrel adapter. The HMLV projectile is slidably attached to the exterior of the barrel adapter. The HMLV projectile includes a launch tube that covers the exit of the barrel adapter. When a first cartridge is fired b the firearm, expanding propellant gas rushes down the adapter bore and out the exit The expanding gas forces the launch tube and the attached HMLV projectile away from the barrel adapter. The HMLV projectile then flies toward a target.

Abstract: The present invention relates to barrel extensions for firearms that have been converted to fire different, most likely lower, caliber ammunition than the firearms were originally designed to accommodate. The present invention in several embodiments is a barrel extension designed to supplement or replace the barrels and/or barrel extensions of firearms that have a sub-caliber conversion installed. Several embodiments of the present invention are configured to be installed on AR15 family rifles with a .22LR ammunition conversion to allow for accurate shooting of the .22LR ammunition through the barrel extension.

Abstract: A shotgun has a telescoping barrel made of concentric barrel sections slidably engaged together. These include at least an inner barrel section and an outer barrel section. A grip on the outer barrel section aids telescopic movement. A locking pin secures or releases the barrel sections. The barrel sections have protrusions that interfere with further outward movement once fully telescoped out. The grip may have a channel to permit a pistol grip to slide onto the grip. A second pistol grip may be connected to the trigger. The butt of the gun may slide out to make a shoulder rest. A butt plate is connected to a rod that slides into and out of the shotgun. The rod has teeth that engage a spring-loaded arm to secure the rod in an extended position. A compression or tension spring may bias the concentric barrel sections in an extended or shortened configuration.

Abstract: A barrel holder for a drop-down barrel weapon with at least one tapped hole for accommodating an interchangeable barrel which ends in a ring shoulder for supporting the edge of a cartridge, wherein a first circumferential section of the ring shoulder is constructed as an axially movable cartridge extractor, and the remaining second circumferential section of the ring shoulder is formed by a separate adapter part which is inserted in modular fashion into the barrel holder.

Abstract: A rifle barrel adapter that ensures adequate mounting overlap for muzzle mounted grenades for proper firing alignment is described, which adapter is formed of only four parts: (1) an elongated unitary body with a narrowed cylindrical front section upon which the muzzle mounted grenade is mounted, which elongated unitary body has an enlarged rear section that is mounted about the muzzle end of the rifle barrel over the flash suppressor; (2) a unitary locking mechanism to secure the elongated unitary body to the muzzle end of the rifle; (3) a bias spring to maintain the unitary locking mechanism in place, and (4) a locking pin to hold the unitary locking mechanism in place within the unitary body.

Abstract: A bullet velocity enhancing rifle attachment assembly a sleeve having a first end, a second end and a perimeter wall. The sleeve has an aperture therein extending into the first end and outwardly of the second end. The aperture is defined by an inner wall including a first portion adjacent to the first end, an second portion adjacent to the second end and a central portion positioned between the first and second portions. The central portion has an toroidal shape. A coupler attached to the second end of the sleeve is releasably engageable with a gun barrel to align the aperture with the gun barrel. Pressure from a front side of a bullet traveling down the gun barrel is forced into the central portion to travel around the toroidal shape and back into the aperture toward the first portion, behind the bullet, as the bullet travels through the central portion.

Abstract: A sabot-retaining shotshell cartridge and firing assembly including a barrel or barrel insert for firing the sabot-retaining shotshell cartridge. The shotshell cartridge includes a cylindrical hull, a sub-caliber projectile, a propellant charge, and a sabot. A central pathway or thin membrane is defined within the base of the sabot between the sub-caliber projectile and propellant charge. The barrel or barrel insert for firing the cartridge includes a transitional area between chamber and sub-caliber rifled bore to retain sabot in the cartridge. Upon cartridge firing, propellant gases flow through central portion of sabot base propelling projectile out of the sabot and into sub-caliber rifled bore.

Abstract: Flash suppressors having novel expansion features are disclosed. In one embodiment, a suppressor includes an attachment portion adapted to attach to a gun barrel, and a suppressor portion coupled to the attachment portion. The suppressor portion has a suppressor bore that is adapted to be aligned with a longitudinal axis of the gun barrel to allow a projectile from the gun barrel to pass therethrough. The suppressor bore is defined by at least one bore surface having at least one expansion groove disposed therein. The expansion groove may be partially-circumferentially disposed about the suppressor bore, or may include a plurality of expansion grooves. In another embodiment, a flash apparatus includes a suppressor portion having a plurality of longitudinally elongated members spaced apart about a circumference of the suppressor bore, each member being separated from adjacent elongated members by a longitudinal slot, at least one longitudinal slot having non-parallel sidewalls.

Abstract: A rifle with a replaceable barrel with two or more barrels for different purposes and calibers and with own magazines for different cartridges. At least one barrel (1) has the cavity (2), into which a projection or upper edge (4) in the cartridge magazine (3) corresponding to the barrel fits, when the right magazine has been inserted into the rifle.

Abstract: A substantially noiseless firearm and ammunition therefor, in which the projectile of the ammunition is attached to the front end of a sabot which fills the cross-sectional area of the barrel and is fired with the projectile. The barrel is provided with lands designed to catch the sabot at the front end of the barrel in such manner that the barrel is sealed off in a gas-proof fashion by the sabot.

Abstract: The present invention is a modular stock system for rifles. The system replaces the rifle's buffer tube with a modified one containing a mount for a constant cheek weld and a rail track for adjustment. A stock module then mounts on the replacement buffer tube. The stock module is interchangeable depending on the user's needs. Various configurations of the stock module are discussed, including adjustable stocks, fixed stocks, and specialized stocks. The stock module may be made even further modular by the addition of rail system.

Abstract: A gun flash hider, formed to include a first expansion chamber, a first flow divider, a plurality of first exhaust passages, an exhaust head, a second expansion chamber, a plurality of second exhaust passages and a second flow divider, whereby high-temperature high-pressure gas produced after firing a bullet undergoes two expansion decompressions and two flow diversion decompressions, through which the gas is sequentially discharged from the first exhaust passages and the second exhaust passages, thereby substantially reducing sonic boom volume, amount of flame and recoil force produced when firing the bullet, and increasing stability and shooting accuracy when using a gun.

Abstract: A sabot-retaining shotshell cartridge and firing assembly including a barrel or barrel insert for firing the sabot-retaining shotshell cartridge. The shotshell cartridge includes a cylindrical hull, a sub-caliber projectile, a propellant charge, and a sabot. A central pathway or thin membrane is defined within the base of the sabot between the sub-caliber projectile and propellant charge. The barrel or barrel insert for firing the cartridge includes a transitional area between chamber and sub-caliber rifled bore to retain sabot in the cartridge. Upon cartridge firing, propellant gases flow through central portion of sabot base propelling projectile out of the sabot and into sub-caliber rifled bore.

Abstract: A display clamp, and related method, are disclosed for removably attaching a second, interchangeable barrel to a fully assembled long gun (i.e., a shotgun or rifle) for display purposes only, wherein the extra barrel's gas cylinder or lug is suspended from the long gun's magazine tube, and held in place by the shotgun's/rifle's removable magazine cap. The method and apparatus allow a retail store (or buyer) to display the firearm and extra barrel as a combination unit either vertically or horizontally oriented within display cases.

Abstract: A non-firing rifle that emulates a semi-automatic or automatic rifle for training in procedures for safe handling, cleaning, and field stripping of such weapons. The non-firing rifle retains the upper receiver assembly, barrel assembly, and ammunition magazine of the emulated rifle, as well as some of the components of the lower receiver assembly of the emulated rifle, but substitutes a modified forging for the lower receiver forging of the emulated rifle. Unlike the lower receiver forging of the emulated rifle, the modified forging has no cutouts to allow a trigger or hammer to be installed. A cutout is provided in a bottom wall of the forging, however, to allow installation of a pseudo-trigger. Accordingly, it is incapable of firing a live ammunition round.

Abstract: A conversion kit and method for converting the RUGER® 10/22® semi-automatic .22 caliber rim fire rifle to shoot .17 HM 2 cartridges utilizes the original bolt in the receiver and replaces the bolt operating handle with increased weight to replace the original bolt handle along with a .17 caliber barrel to permit the modified rifle to safely fire, eject and reload the .17 caliber cartridges.

Abstract: A multi-purposes mechanism for shooting apparatus includes a gun body, a barrel, a shooting member, and a rear cap. The gun body comprises a hollow tube perpendicularly interconnecting with a first loading hole at a center portion of the hollow tube. A first stage is formed on an inner wall of the tube in front of the first loading hole. A second stage is formed on the inner wall of the tube in back of the first loading hole. The barrel is disposed in the tube before the first loading hole, and has a first engaging ring corresponding to the first stage of the tube. The shooting member is disposed in the tube after the first loading hole, and has a second engaging ring on an outer wall thereof corresponding to the second stage of the tube. The rear cap is connected to a rear end of the tube.

Abstract: Practice barrels for use with practice cartridges are described herein. An example practice device for use with self-loading grenade launchers includes a practice barrel having a practice cartridge chamber to receive a practice cartridge. A live cartridge does not correspond to the practice cartridge chamber. Additionally, the live cartridge is unable to be properly positioned within the practice barrel to prevent ignition of the live cartridge. Further, the practice cartridge chamber is cushioned to substantially absorb a breech energy to substantially prevent damage to the practice barrel.

Abstract: A semi-automatic rifle kit comprises a receiver; first and second bolt assemblies that can be interchangeably inserted inside the receiver when no barrel is coupled to the receiver; and first and second barrels that can be interchangeably coupled to the receiver when no bolt assembly is inserted inside the receiver. The first bolt assembly can be inserted inside the receiver when the first barrel is coupled to the receiver, but not when the second barrel is coupled to the receiver. The second bolt assembly can be inserted inside the receiver when the second barrel is coupled to the receiver, but not when the first barrel is coupled to the receiver. The first bolt assembly and the first barrel are designed for use with a first type of cartridge, but not a second type of cartridge. The second bolt assembly and the second barrel being are designed for use with the second type of cartridge, but not the first type of cartridge.

Abstract: A pistol has a forwardly extending cylindrical shaft with a cylindrical bearing surface. A rotatable cylinder is mounted on the bearing surface. A cylindrical chamber in the rotatable cylinder receives a cartridge. A firing pin ring with a firing pin aligned with the chamber is mounted on the bearing surface. A hammer safety lock includes a hole in the firing pin ring with a rearwardly extending pin. A barrel receives the cylindrical shaft. A barrel sleeve is positioned between the barrel and the shaft. A cartridge extraction tool is operable after axial sliding and separation between the cylinder and the cylindrical shaft. The cartridge extraction tool is adapted to be inserted into the chamber of the cylinder from the end remote from the firing pin ring to remove a cartridge.

Abstract: Practice barrels for use with practice cartridges are described herein. An example practice device for use with self-loading grenade launchers includes a practice barrel having a practice cartridge chamber to receive a practice cartridge. A live cartridge does not correspond to the practice cartridge chamber. Additionally, the live cartridge is unable to be properly positioned within the practice barrel to prevent ignition of the live cartridge. Further, the practice cartridge chamber is cushioned to substantially absorb a breech energy to substantially prevent damage to the practice barrel.

Abstract: A display clamp assembly, and a related method, are disclosed for removably attaching a second barrel to a shotgun for display purposes, allowing a retail store (or a buyer) to display the firearm as a combination unit in a display case. The extra barrel is attached onto and substantially parallel to the barrel of the fully assembled shotgun. In the preferred embodiment, the display clamp is longitudinally split into two halves. The two halves are mirror images that can be bolted together, along their midsections. When joined, the two halves form collars on opposite ends. One collar is designed to snugly fit around the barrel of an assembled shotgun. The second collar has flared ends that guide the second barrel into the clamp.

Abstract: A system that converts an original equipment (OEM) AR-15 rifle to a rifle capable of firing cartridges of at least two different calibers. Two or more barrel liners are provided for cartridges of differing calibers. Each liner is insertable through a rear opening of an upper receiver portion of the rifle and into a smooth bore barrel of a modified barrel assembly. Each liner comprises a tube portion having a longitudinal bore and a head portion with an opening that communicates with said bore. An adapter bolt carrier assembly is substituted for the OEM AR-15 bolt carrier assembly. The substituted assembly includes a bolt that carries the firing pin and is slidably mounted on a rail guide. A front end of the rail guide has a tongue extension with a slot that receives a pin attached to a rear end of a liner head. A support rail is fixed to a rear end of the rail guide. A spring extends from the support rail to the bolt, thereby pressing the bolt against the liner head.

Abstract: A training mortar apparatus includes a small mortar tube and a large mortar tube, the small mortar tube being disposed in the large mortar tube; a removable base cap attached to one end of the small mortar tube; a plug inserted in the removable base cap; a removable firing pin inserted in the plug; a second base cap attached to one end of the large mortar tube; and at least one opening in the large mortar tube, the opening being axially aligned with the removable firing pin of the small mortar tube. Improved manufacturing methods are also disclosed.