Abstract: Disclosed herein is a method and apparatus for replacing a selector switch of lower receiver of a firearm, the method including the steps of: removing an ancillary portion of the selector switch; inserting a sear spring and sear deflector block into the lower receiver such that a hook portion and an end portion of the sear spring engage a sear and a portion of a sear spring to cause the sear and the portion of a sear spring to be disengaged from the selector switch; inserting a detent deflector button into a side of the lower receiver such a spring biased detent is depressed and the selector switch extends from an opposite side of the lower receiver; removing the selector switch; inserting a new selector switch into the opposite side of the lower receiver such that the detent deflector button is dislodged from the side of the lower receiver; removing the sear spring and sear deflector block; and securing the removing the ancillary portion or a new ancillary portion to the new selector switch.

Abstract: A rifle configured for firing a 7.62×39 mm round is provided. The rifle having: an upper receiver; a lower receiver, the upper receiver being removably secured to the lower receiver, wherein the lower receiver is configured to removably receive and secure a magazine therein, the magazine being configured to hold at least 30 rounds of a 7.62×39 mm ammunition; and wherein a magazine well of the lower receiver is configured to receive an adapter at a front of the lower receiver.

Abstract: An upper receiver for a weapon, the upper receiver having a plurality channels each being oriented in a first direction and wherein each of the plurality of channels intersect an elongated channel extending in a second direction; a modular rail having a pair of securement features configured to be slidably received within a pair of the plurality of channels such that modular rail can slide in the pair of the plurality of channels in the first direction until the pair of features can slide within the elongated channel in the second direction.

Abstract: A gas regulator for a rifle, having: an elongated member having a first end and a second end; a head portion located at the first end; a pair of openings passing through the elongated member, wherein one of the pair of openings is larger than the other one of the pair of openings; a recessed area located at the second end; and wherein the gas regulator is located in a front sight of the rifle, the sight, comprising: a mounting block; a tower pivotally mounted to the mounting block for movement between a first position and a second position; a first locking mechanism comprising a plurality of spring biased members for retaining the tower in the first position and the second position, the plurality of spring biased members being configured to allow movement of the tower between the first position and the second position in response to a force applied to the tower; and a second locking mechanism configured to lock the tower in the second position, wherein the second locking mechanism must be manually released be

Abstract: A gas regulator for a rifle, having: an elongated member having a first end and a second end; a head portion located at the first end; a pair of openings passing through the elongated member, wherein one of the pair of openings is larger than the other one of the pair of openings; a recessed area located at the second end; and a pair of detent openings located on a portion of the elongated member, the pair of detent openings being spaced from each other and located within another recessed area located on a surface of the elongated member between the first end and the second end, wherein one of the pair of detent openings is closer to the first end than the other one of the pair of detent openings.

Abstract: An automatic or semi-automatic rifle. The rifle has a receiver and a bolt having a striking surface, the bolt enclosed within the receiver. A barrel has a bore, the barrel coupled to the receiver. An indirect gas operating system has a cylinder and a piston, the indirect gas operating system mounted with a mounting structure substantially independent of the barrel. The cylinder is in communication with the bore, and the piston is fitted to the cylinder and disposed for striking the striking surface and displacing the bolt assembly.

Abstract: A firearm having a lower receiver is provided. The receiver is adapted to couple with a plurality of upper receivers having different calibers. The lower receiver comprises a receiver extension having an opening therein. A spring is disposed within the opening. A buffer member is provided having a first portion having an end. The buffer member is coupled to the spring within the opening, wherein the buffer member is movable between a first position where the end is within the opening and a second position wherein the end external to the opening.

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: An upper receiver for a firearm, the upper receiver having: a hand guard section removably connected to the upper receiver via a locking mechanism pivotally mounted to the hand guard section for movement between a locking position and an unlocking position, wherein the locking mechanism requires only a single movement in one direction to move from the locking position to the unlocking position, wherein the hand guard section has peripheral device mounting rails located at a six o'clock position with respect to a centerline of the barrel and wherein the hand guard section is capable of being completely detached and removed from the upper receiver after the locking mechanism has been moved into the unlocking position; and a plurality of integrally formed rails located above the hand guard section and at three, nine and twelve o'clock positions with respect to the centerline of the barrel.

Abstract: A method of providing a semi-automatic rifle with a reversible safety selector is provided.

Abstract: An upper receiver for a firearm is provided. The upper receiver having: a hand guard section integrally formed with the upper receiver; a rail section integrally formed with the hand guard section, wherein the rail section is formed of a first material and the hand guard section is formed of a second material, wherein the second material is molded about the first material.

Abstract: A firearm having a lower receiver is provided. The receiver is adapted to couple with a plurality of upper receivers having different calibers. The lower receiver comprises a receiver extension having an opening therein. A spring is disposed within the opening. A buffer member is provided having a first portion having an end. The buffer member is coupled to the spring within the opening, wherein the buffer member is movable between a first position where the end is within the opening and a second position wherein the end external to the opening.

Abstract: A front sight for a weapon, the front sight having: a mounting block; a tower pivotally mounted to the mounting block for movement between a first position and a second position; a first locking mechanism comprising a plurality of spring biased members for retaining the tower in the first position and the second position, the plurality of spring biased members being configured to allow movement of the tower between the first position and the second position in response to a force applied to the tower; and a second locking mechanism configured to lock the tower in the second position, wherein the second locking mechanism must be manually released before the tower can be moved from the second position to the first position.

Abstract: A rifle configured for firing a 7.62×39 mm round is provided. The rifle having: an upper receiver; a lower receiver, the upper receiver being removably secured to the lower receiver, wherein the lower receiver is configured to removably receive and secure a magazine therein, the magazine being configured to hold at least 30 rounds of a 7.62×39 mm ammunition; and wherein a magazine well of the lower receiver is configured to receive an adapter at a front of the lower receiver.

Abstract: An upper receiver for a weapon, the upper receiver having a plurality channels each being oriented in a first direction and wherein each of the plurality of channels intersect an elongated channel extending in a second direction; a modular rail having a pair of securement features configured to be slidably received within a pair of the plurality of channels such that modular rail can slide in the pair of the plurality of channels in the first direction until the pair of features can slide within the elongated channel in the second direction.

Abstract: A gas regulator for a rifle is provided, the gas regulator having: an elongated member having a first end and a second end; a head portion located at the first end; a pair of openings passing through the elongated member, wherein one of the pair of openings is larger than the other one of the pair of openings; and a recessed area located at the second end.

Abstract: A modular rail system for an upper receiver of a firearm is provided, the modular rail system having: a bottom portion configured to be removably secured to the upper receiver, wherein the bottom portion has an integrally formed bottom rail and a forward portion located forward of a top rail of the upper receiver; an upper rail extension configured to be removably secured to the forward portion of the bottom portion; and a release mechanism for releasably securing the upper portion to the forward portion of the bottom portion.

Abstract: A front sight for a weapon, the front sight having: a mounting block; a tower pivotally mounted to the mounting block for movement between a first position and a second position; a first locking mechanism comprising a plurality of spring biased members for retaining the tower in the first position and the second position, the plurality of spring biased members being configured to allow movement of the tower between the first position and the second position in response to a force applied to the tower; and a second locking mechanism configured to lock the tower in the second position, wherein the second locking mechanism must be manually released before the tower can be moved from the second position to the first position.

Abstract: A rifle having a receiver with an integral hand guard and a barrel. The barrel is connected to the receiver. The hand guard extends over and surrounds the barrel. A removable hand guard is attached to the receiver by an attachment that stably holds the removable hand guard to the receiver. The attachment is arranged for allowing detachment and removal of the removable hand guard from the receiver without removal of fasteners.