A firearm barrel has an elongated body defining a bore and defining a bore axis, the body defining a breech end and an opposed muzzle end, a chamber defined in the breech end and contiguous with the bore; the bore having an interior surface having a plurality of alternating lands and grooves, the grooves being surfaces separated from the bore axis by first radius, the lands being surfaces separated from the bore axis by second radius less than the first radius and the lands and grooves being straight elements parallel to the bore axis, such that no spin is imparted to a projectile propelled down the bore. The lands and grooves may extend from the chamber to the muzzle end. The bore may have a constant cross-sectional profile along its length.

A gas operated firearm barrel has a gas port angled through the wall thereof at an angle from adjacent the barrel muzzle rearward to the barrel bore to thereby allow the shortening of the barrel while maintaining the distance of the gas port bore opening from the barrel muzzle. The process of making a gas port in a barrel in accordance with the present invention is also taught.

A gas operated firearm barrel has a gas port angled through the wall thereof at an angle from adjacent the barrel muzzle rearward to the barrel bore to thereby allow the shortening of the barrel while maintaining the distance of the gas port bore opening from the barrel muzzle. The process of making a gas port in a barrel in accordance with the present invention is also taught.

Disclosed is a firearm configuration for a handgun. The firearm configuration is designed to reduce the recoil forces encountered by a user upon firing the weapon. It further includes a recoil plate that absorbs forces generated by the slide during firing. Recoil forces are reduced by lowering the firearm's center of mass and by aligning a recoiling mass with the user's arm and trigger finger. The firearm configuration further includes a locking block which prevents rotational and lateral movement of the barrel upon firing.

A conversion kit for a firearm of the type having a removable component is disclosed. The conversion kit includes a chamber piece having a coupling end, and a muzzle piece of a conversion barrel having a coupling end configured to be secured to the coupling end of the chamber piece and an engagement end. The engagement end is configured to mate with the removable component such that manipulation of the removable component causes the coupling end of the muzzle piece of the conversion barrel to be secured to the coupling end of the chamber piece.

A conversion kit for a firearm of the type having a removable component is disclosed. The conversion kit includes a chamber piece having a coupling end, and a muzzle piece of a conversion barrel having a coupling end configured to be secured to the coupling end of the chamber piece and an engagement end. The engagement end is configured to mate with the removable component such that manipulation of the removable component causes the coupling end of the muzzle piece of the conversion barrel to be secured to the coupling end of the chamber piece.

An upper receiver assembly for a firearm having an upper receiver with an integral barrel nut, a handguard assembly and a barrel nut assembly with a barrel and lock nut is provided. The barrel is received by the upper receiver and is secured directly to the upper receiver using the lock nut. The upper receiver also includes an integral handguard mounting member to which the handguard assembly may be directly attached. The upper receiver assembly allows the user to attach both the barrel and handguard assemblies directly to the upper receiver, independently of one another.

An upper receiver assembly for a firearm having an upper receiver with an integral barrel nut, a handguard assembly and a barrel nut assembly with a barrel and lock nut is provided. The barrel is received by the upper receiver and is secured directly to the upper receiver using the lock nut. The upper receiver also includes an integral handguard mounting member to which the handguard assembly may be directly attached. The upper receiver assembly allows the user to attach both the barrel and handguard assemblies directly to the upper receiver, independently of one another.

A bottleneck cartridge chamber wherein a circumferential relief recess is placed within the shoulder region of the chamber. As opposed to the continuous angled shoulder of conventional cartridge chambers, the proposed relief recess is envisioned as an angular segment of larger included angle than the conventional chamber shoulder angle (thereby creating a compound angle cartridge chamber shoulder region) or a radial recess that would eliminate a portion of the conventional chamber shoulder.

An integrated fixed sight on a firearm consists of a front sighting device and an external muzzle device. The external muzzle device includes a proximal end, a central axis, a mount body, a top surface, and a distal end. The front sighting device is laterally aligned with the central axis and mounted onto the top surface adjacent the proximal end. The front sighting device can vary in size and shape. The external muzzle device is mounted onto the barrel of the firearm through a clamp and a fastening mechanism. Since the threads on the barrel are not used, the threads of the barrel are preserved.