An AR-type rifle lower receiver comprises a lower portion having a supplemental opening or recess adjacent the rifle's trigger-guard opening for receiving the middle finger of the user's hand. In addition, a juxtaposed curved boundary surface spaced laterally and rearwardly with respect to the supplemental opening is provided to define a comfortable “grip” bearing surface for the area between the thumb and index finger of the user's hand when the user positions his/her index finger on the rifle's trigger.

A magazine for a firearm with a magazine well and a reciprocating bolt. A body of the magazine is engaged within the well and has a top, interconnected front, sides and rear walls, and a bottom defining a cartridge holding interior. A spring supported within the interior contacts the bottom and upwardly biases a follower positioned atop the spring toward an opening in the top, through which the cartridges are loaded into the magazine. A feed tower integrated into the top supports a pair of feed lips positioned along opposed edges defining the opening. An aperture is formed in the top rearward of the feed tower. A rear upward projection of the follower aligns with the aperture and, following discharge of a final cartridge, elevates above the top in order to actuate a separate bolt catch or bolt hold open adaptor to prevent a forward returning motion of the bolt.

A magazine for a firearm with a magazine well and a reciprocating bolt. A body of the magazine is engaged within the well and has a top, interconnected front, sides and rear walls, and a bottom defining a cartridge holding interior. A spring supported within the interior contacts the bottom and upwardly biases a follower positioned atop the spring toward an opening in the top, through which the cartridges are loaded into the magazine. A feed tower integrated into the top supports a pair of feed lips positioned along opposed edges defining the opening. An aperture is formed in the top rearward of the feed tower. A rear upward projection of the follower aligns with the aperture and, following discharge of a final cartridge, elevates above the top in order to actuate a separate bolt catch or bolt hold open adaptor to prevent a forward returning motion of the bolt.

Firearms with combined bolt catch and ejector have a bolt defining a bolt face configured to receive a case head of a cartridge, a bolt catch connected to a frame and movable between a first operational position in which bolt reciprocation forward from the rear position is enabled, and a second restraining position in which a portion of the bolt catch restrains the bolt in the rear position, and the bolt catch having an ejector surface portion positioned clear of the bolt face when the bolt catch is in the first operational position and in registration with a portion of the bolt face when the bolt catch is in the second restraining position such that a case head received by the bolt face strikes the ejector surface portion upon movement of the bolt from the forward to the rearward position when the bolt catch is in the second restraining position.

Firearms with combined bolt catch and ejector have a bolt defining a bolt face configured to receive a case head of a cartridge, a bolt catch connected to a frame and movable between a first operational position in which bolt reciprocation forward from the rear position is enabled, and a second restraining position in which a portion of the bolt catch restrains the bolt in the rear position, and the bolt catch having an ejector surface portion positioned clear of the bolt face when the bolt catch is in the first operational position and in registration with a portion of the bolt face when the bolt catch is in the second restraining position such that a case head received by the bolt face strikes the ejector surface portion upon movement of the bolt from the forward to the rearward position when the bolt catch is in the second restraining position.

A bolt stop actuator is disclosed. The actuator may include a lift arm, a first leg extending from a point proximate to an end of the lift bar and generally perpendicular therefrom, a second leg extending in the same direction from the lift bar as the first leg, and a projection extending from the lift bar and configured to contact a follower of an empty magazine when the bolt stop actuator is assembled into a firearm. Neither the first leg, nor the second leg, include apertures positioned distal to the lift arm.

A combined firearm receiver and rail includes a handguard rail and a receiver housing disposed within the handguard rail. The handguard rail includes one of a takedown lug clearance slot, a handguard magazine port, a handguard continuous rail, a handguard ejection port, an attachment location, accessory attachment points, a handguard charging handle latch retaining slot, a charging handle housing, a charging handle guideway, a bolt catch clearance slot, a barrel cavity, a receiver cavity, an exhaust port, and a handguard section. In one variation, the handguard section does not come into physical contact with a barrel or a barrel nut of the firearm.

A combined firearm receiver and rail includes a handguard rail and a receiver housing disposed within the handguard rail. The handguard rail includes one of a takedown lug clearance slot, a handguard magazine port, a handguard continuous rail, a handguard ejection port, an attachment location, accessory attachment points, a handguard charging handle latch retaining slot, a charging handle housing, a charging handle guideway, a bolt catch clearance slot, a barrel cavity, a receiver cavity, an exhaust port, and a handguard section. In one variation, the handguard section does not come into physical contact with a barrel or a barrel nut of the firearm.

The invention relates to a breech system for a firearm, having a bolt receiver and a bolt; the bolt receiver is embodied in the form of a hollow cylinder at least with engagement means protruding radially inward and there is also at least one bolt head, which has outward-protruding engagement means that correspond to the inward-protruding engagement means; the bolt head is supported in rotary fashion on a bolt carrier and there is also a bolt body, which is able to slide on a bolt head shaft of the bolt head, and between the bolt body and the bolt carrier, there is at least one compression spring, which tends to move the bolt body in the direction toward the bolt head; and on the bolt head shaft and on the bolt body, there are means that produce a rotation of the bolt head when the bolt body is slid on the bolt head shaft.

The invention relates to a breech system for a firearm, having a bolt receiver and a bolt; the bolt receiver is embodied in the form of a hollow cylinder at least with engagement means protruding radially inward and there is also at least one bolt head, which has outward-protruding engagement means that correspond to the inward-protruding engagement means; the bolt head is supported in rotary fashion on a bolt carrier and there is also a bolt body, which is able to slide on a bolt head shaft of the bolt head, and between the bolt body and the bolt carrier, there is at least one compression spring, which tends to move the bolt body in the direction toward the bolt head; and on the bolt head shaft and on the bolt body, there are means that produce a rotation of the bolt head when the bolt body is slid on the bolt head shaft.