A shotgun ammunition conversion system has a detachable magazine well having a sleeve defining a rectangular passage adapted to removably receive an ammunition magazine, a boss extending forward of the sleeve and at a level above at least a portion of the sleeve, the boss being adapted to be received in the rear aperture of the magazine tube, and a tang extending rearward of the sleeve and defining a tang aperture operable to receive a fastener associated with a shotgun frame to secure the magazine well to the shotgun with the sleeve proximate and aligned with the loading port when the boss is received in the rear aperture of the magazine tube. The boss may have a lower cylindrical surface portion operable to contact a lower portion of the magazine tube adjacent to the rear aperture. The boss may be a cylindrical body.

A shotgun ammunition conversion system has a detachable magazine well having a sleeve defining a rectangular passage adapted to removably receive an ammunition magazine, a boss extending forward of the sleeve and at a level above at least a portion of the sleeve, the boss being adapted to be received in the rear aperture of the magazine tube, and a tang extending rearward of the sleeve and defining a tang aperture operable to receive a fastener associated with a shotgun frame to secure the magazine well to the shotgun with the sleeve proximate and aligned with the loading port when the boss is received in the rear aperture of the magazine tube. The boss may have a lower cylindrical surface portion operable to contact a lower portion of the magazine tube adjacent to the rear aperture. The boss may be a cylindrical body.

A modular handgun system comprises an elongated universal trigger frame having a barrel locking block, a pair of slide rails, and an accessory rail. The trigger frame is adapted to have a trigger assembly mounted thereto. The system further comprises a grip frame having an elongated channel and a hand grip extending downwardly from the elongated channel. The trigger frame is removably mounted in the elongated channel of the grip frame. The accessory rail of the trigger frame is positioned forward of a forward end of the elongated channel of the grip frame so as to be exposed. The system further comprises a slide and barrel assembly slidably mounted on the slide rails of the trigger frame.

A modular handgun system comprises an elongated universal trigger frame having a barrel locking block, a pair of slide rails, and an accessory rail. The trigger frame is adapted to have a trigger assembly mounted thereto. The system further comprises a grip frame having an elongated channel and a hand grip extending downwardly from the elongated channel. The trigger frame is removably mounted in the elongated channel of the grip frame. The accessory rail of the trigger frame is positioned forward of a forward end of the elongated channel of the grip frame so as to be exposed. The system further comprises a slide and barrel assembly slidably mounted on the slide rails of the trigger frame.

A switch barrel recoil lug for clamping together a rifle action and a rifle barrel having a body with a barrel shank bore hole and a split section allowing expansion and contraction of the barrel shank bore hole, an index pin hole or threaded holes for aligning and connecting the body to the rifle action and a stock flange for engaging a rifle stock wherein the barrel shank bore hole has a tapered surface matching a tapered surface on a barrel shank of the rifle barrel.

A detachable chassis base for a tactical rifle is presented. The lower chassis receiver assembly can have a detachable chassis base that substantially selectively attaches to the chassis receiver interface. The detachable chassis base can be completely removable, or it can be hingedly attached to provide access without completely removing the chassis base, or a combination thereof. Multiple combinations of parts included in the detachable chassis base are possible. Several variations and combinations are illustrated herein, although others are contemplated.

A detachable chassis base for a tactical rifle is presented. The lower chassis receiver assembly can have a detachable chassis base that substantially selectively attaches to the chassis receiver interface. The detachable chassis base can be completely removable, or it can be hingedly attached to provide access without completely removing the chassis base, or a combination thereof. Multiple combinations of parts included in the detachable chassis base are possible. Several variations and combinations are illustrated herein, although others are contemplated.

A system for firing reduced energy cartridges from a modern sporting rifle utilizes a bolt assembly weighing less than a conventional bolt assembly for such rifles and utilizes blow back for cycling the bolt assembly rather than gas operation. A bolt insert in a polymer bolt carrier of the bolt assembly has a projection that fits within a recess on the rear face of reduced energy cartridges. The reduced energy cartridges having a polymer casing, a rimfire power load for propellant, the power load recessed from the rear face of the casing. Tuning the bolt may comprise adjusting the weight of the bolt or the sliding resistance of the bolt assembly in the upper receiver. The bolt may be formed by metal injection molding with a polymer bolt carrier attached thereto.

A firearm for firing case-telescoped (CT) rounds includes a barrel configured for transit of a bullet of a live CT cartridge in a live-fire operating mode. The live CT cartridge is chambered and fired from a live-fire chamber installed in the live-fire operating mode. The firearm further includes a blank-fire chamber configured to chamber and fire a blank CT cartridge in a blank-fire operating mode, wherein the blank-fire chamber has a second diameter less than a first diameter of the live-fire chamber, to prevent chambering of the live CT cartridge in the blank-fire operating mode. The arrangement can enhance safety by preventing accidental firing of a live round during operation when it is assumed that only blanks are being fired.

A firearm for firing case-telescoped (CT) rounds includes a barrel configured for transit of a bullet of a live CT cartridge in a live-fire operating mode. The live CT cartridge is chambered and fired from a live-fire chamber installed in the live-fire operating mode. The firearm further includes a blank-fire chamber configured to chamber and fire a blank CT cartridge in a blank-fire operating mode, wherein the blank-fire chamber has a second diameter less than a first diameter of the live-fire chamber, to prevent chambering of the live CT cartridge in the blank-fire operating mode. The arrangement can enhance safety by preventing accidental firing of a live round during operation when it is assumed that only blanks are being fired.