A universal firearm-mounted receiving apparatus adapted to receive an ejected casing from a firearm (FIG. 1). The apparatus has an arm with a mounting piece disposed at one end and a receptacle for shell casings disposed at the other end (opposite to) mounting piece. The arm further contains one or more hinges that allow(s) at least a portion of the arm to move independently of another portion, thereby making the arm and receptacle positionable for a variety of different firearms.

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 universal firearm-mounted receiving apparatus adapted to receive an ejected casing from a firearm (FIG. 1). The apparatus has an arm with a mounting piece disposed at one end and a receptacle for shell casings disposed at the other end (opposite to) mounting piece. The arm further contains one or more hinges that allow(s) at least a portion of the arm to move independently of another portion, thereby making the arm and receptacle positionable for a variety of different firearms.

A dust cover for a firearm is provided. The cover includes a panel and a first extension extending from the panel and configured for engaging with the firearm to selectively secure the panel to the firearm. The panel is pivotable about the first extension to define a pivot point for pivoting the panel from a first position that encloses an opening or ejection port of the firearm and a second position in which the opening is not enclosed. The first extension is retractable relative to the panel to thereby allow for the selective engagement of the dust cover to the firearm. A related method of installing or replacing the dust cover is also provided.

A multi-caliber firearm includes a barrel extension configured to connect to an interchangeable barrel that is selected from at least two predetermined caliber sizes. An interchangeable magazine well receives a magazine that is selected to house cartridges from the predetermined caliber sizes. The magazine well includes a first end facing towards the stock and a second end facing towards the barrel extension. A bolt carrier group includes a bolt carrier and a bolt. A reverse movement unloads a used cartridge from the bolt and a forward movement loads a new cartridge from the magazine. The bolt carrier group receives an interchangeable bolt that is selected to load and unload one of the predetermined caliber sizes. The bolt includes a longitudinal cartridge retaining notch facing towards the magazine. The cartridge retaining notch is configured to retain the new cartridge in the magazine during the reverse movement.

A multi-caliber firearm includes a barrel extension configured to connect to an interchangeable barrel that is selected from at least two predetermined caliber sizes. An interchangeable magazine well receives a magazine that is selected to house cartridges from the predetermined caliber sizes. The magazine well includes a first end facing towards the stock and a second end facing towards the barrel extension. A bolt carrier group includes a bolt carrier and a bolt. A reverse movement unloads a used cartridge from the bolt and a forward movement loads a new cartridge from the magazine. The bolt carrier group receives an interchangeable bolt that is selected to load and unload one of the predetermined caliber sizes. The bolt includes a longitudinal cartridge retaining notch facing towards the magazine. The cartridge retaining notch is configured to retain the new cartridge in the magazine during the reverse movement.