The barrel of a pistol, specifically in a short recoil operated pistol, is comprised of multiple bearings surfaces comprised of cams and lugs that allow the pistol to function. The surfaces mechanically delay the pistol enough to allow the pistol to reliably function in the manner of an automatic firearm, chambering a round at the end of each cycle of operation. A barrel that locates a forward lug positioned horizontally in front of the trigger guard of the pistol with side cams that are shallow and interact in a way to provide the pistol with a robust and consistent lock up from shot to shot to provide an advantage in the function of the firearm.

A firearm having reduced muzzle rise is disclosed. The firearm includes a barrel having a breech end, an opposing muzzle end, and a bore defining a barrel centerline which, when extended in a longitudinal direction, defines a barrel axis. The firearm further includes a magazine tube disposed above the barrel, a receiver defining a lower opening to receive the barrel, and an upper opening to receive the magazine tube. The firearm further includes a stock defining a body support surface where the stock braces against a user's body. The barrel axis passes through the body support surface of the stock.

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. A short-recoil action also enables the shotgun to function reliably with shorter length barrels.

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. A short-recoil action also enables the shotgun to function reliably with shorter length barrels.

A break open rifle and bolt action rifle having a barrel extension with a breech end for receiving a propellant charge, a muzzle end with an extended attachment structure for receiving a complementary attachment structure of a barrel, and a chamber disposed within and through the barrel extension having a first diameter at a first end and a narrowing portion adjacent a second end opposite the first end, the narrowing portion having a second diameter smaller than the first diameter, wherein the first diameter of the chamber is sized to receive the propellant charge therein, and the second diameter of the narrowing portion is sized to prevent the propellant charge from being further inserted past the narrowing portion, and to prevent a projectile from being inserted through the chamber from the barrel muzzle end. A bolt action configuration having dual diameter non-rotating bolt with an extractor and ejector mechanism for removing a propellant charge.

A break open rifle and bolt action rifle having a barrel extension with a breech end for receiving a propellant charge, a muzzle end with an extended attachment structure for receiving a complementary attachment structure of a barrel, and a chamber disposed within and through the barrel extension having a first diameter at a first end and a narrowing portion adjacent a second end opposite the first end, the narrowing portion having a second diameter smaller than the first diameter, wherein the first diameter of the chamber is sized to receive the propellant charge therein, and the second diameter of the narrowing portion is sized to prevent the propellant charge from being further inserted past the narrowing portion, and to prevent a projectile from being inserted through the chamber from the barrel muzzle end. A bolt action configuration having dual diameter non-rotating bolt with an extractor and ejector mechanism for removing a propellant charge.

A shotgun is formed of sub-assemblies which include a lower receiver upon which a butt stock and an upper receiver are mounted. The lower receiver houses the fire control mechanism, the butt stock includes an ammunition elevator and a breech cover. Magazine tubes, ammunition cut-offs, a selector, a selector interrupter and the barrel are mounted on the upper receiver.

A firearm having reduced muzzle rise is disclosed. The firearm includes a barrel having a breech end, an opposing muzzle end, and a bore defining a barrel centerline which, when extended in a longitudinal direction, defines a barrel axis. The firearm further includes a magazine tube disposed above the barrel, a receiver defining a lower opening to receive the barrel, and an upper opening to receive the magazine tube. The firearm further includes a stock defining a body support surface where the stock braces against a user's body. The barrel axis passes through the body support surface of the stock.

A rifle platform with semi-automatic, select fire, and/or fully automatic shooting options uses a pistol cartridge. The rifle barrel includes an extension having a ramp for loading the cartridges and having a key way for the shell extractor. The magazine of the rifle is mounted to the lower receiver so as to load the cartridges in a direction perpendicular to the rifle barrel. The magazine follower automatically locks the bolt after the last cartridge is fired. The bolt and bolt carrier are integrally machined, and fully enclose the cartridge to preclude out of battery firing.

A rifle platform with semi-automatic, select fire, and/or fully automatic shooting options uses a pistol cartridge. The rifle barrel includes an extension having a ramp for loading the cartridges and having a key way for the shell extractor. The magazine of the rifle is mounted to the lower receiver so as to load the cartridges in a direction perpendicular to the rifle barrel. The magazine follower automatically locks the bolt after the last cartridge is fired. The bolt and bolt carrier are integrally machined, and fully enclose the cartridge to preclude out of battery firing.