Abstract: A firearm with a lower receiver and bolt catch assembly, the bolt catch assembly may include a left-side control, a right-side control, a bolt catch connected to the left-side control, and a bolt catch extension connecting the bolt catch to the right-side control. The bolt catch assembly may fit with a bolt catch recess of the lower receiver such that the left side control extends from a left side of the lower receiver, and the right-side control extends generally rearward along a right side of the lower receiver.

Abstract: A cam pin configured to be moveably constrained within a cam slot of a firearm bolt carrier and configured to be operatively connected to a firearm bolt, the cam pin having a cam pin shaft with a firing pin opening. The cam pin head of the cam pin is configured to contact the upper receiver via a cam pin head contact surface that has a reduced contact surface area or length.

Abstract: A firearm with a lower receiver and bolt catch assembly, the bolt catch assembly may include a left-side control, a right-side control, a bolt catch connected to the left-side control, and a bolt catch extension connecting the bolt catch to the right-side control. The bolt catch assembly may fit with a bolt catch recess of the lower receiver such that the left side control extends from a left side of the lower receiver, and the right-side control extends generally rearward along a right side of the lower receiver.

Abstract: A firearm, top cover, and feed lever. The feed lever includes a feed lever body having a feed lever track, wherein the feed lever body is configured to be pivotally mounted within a topcover assembly, and wherein the feed lever body is configured to pivot in response to a force transmitted by a roller of an operating group to the feed lever track during cycling of the firearm. The feed lever further includes a feed lever track first end, wherein the feed lever track first end comprises a feed lever track exit portion configured to receive the roller of the operating group after the roller exits the feed lever track via the feed lever track exit portion as the firearm cycles.

Abstract: A firearm with a lower receiver and bolt catch. The lower receiver may include a first external wall portion that is on the left side of the firearm and a second external wall portion on the right side of the firearm when a front of the lower receiver is facing forward, the rear of lower receiver is facing rearward, the bottom of the lower receiver is facing downward, and the firearm is in a firing position. The firearm may further include a bolt catch for preventing forward movement of the bolt. The bolt catch may include a first external bolt catch portion that exits the first external wall portion of the receiver on the left side of the firearm and a second external bolt catch portion that exits the second external wall portion of the receiver on the right side of the firearm.

Abstract: A firearm with a lower receiver and bolt catch. The lower receiver may include a first external wall portion that is on the left side of the firearm and a second external wall portion on the right side of the firearm when a front of the lower receiver is facing forward, the rear of lower receiver is facing rearward, the bottom of the lower receiver is facing downward, and the firearm is in a firing position. The firearm may further include a bolt catch for preventing forward movement of the bolt. The bolt catch may include a first external bolt catch portion that exits the first external wall portion of the receiver on the left side of the firearm and a second external bolt catch portion that exits the second external wall portion of the receiver on the right side of the firearm.

Abstract: A firearm with a lower receiver and bolt catch. The lower receiver may include a first external wall portion that is on the left side of the firearm and a second external wall portion on the right side of the firearm when a front of the lower receiver is facing forward, the rear of lower receiver is facing rearward, the bottom of the lower receiver is facing downward, and the firearm is in a firing position. The firearm may further include a bolt catch for preventing forward movement of the bolt. The bolt catch may include a first external bolt catch portion that exits the first external wall portion of the receiver on the left side of the firearm and a second external bolt catch portion that exits the second external wall portion of the receiver on the right side of the firearm.

Abstract: A hammer usable with a firearm having a bolt carrier that is configured to travel forward and rearward within the firearm during a firing operation of the firearm. The hammer includes a mounting portion configured to rotatably constrain the hammer within the firearm and a firing pin contact portion configured to rotate upward to a vertical most position and contact a firing pin. The hammer further includes a sear notch configured to contact a trigger, and an extended surface that is configured to contact a bottom portion of the bolt carrier when the bolt carrier travels in a rearward direction after firing of the firearm. The extended surface allows for additional travel of a bolt carrier group of the firearm.

Abstract: A firearm with a lower receiver and bolt catch. The lower receiver may include a first external wall portion that is on the left side of the firearm and a second external wall portion on the right side of the firearm when a front of the lower receiver is facing forward, the rear of lower receiver is facing rearward, the bottom of the lower receiver is facing downward, and the firearm is in a firing position. The firearm may further include a bolt catch for preventing forward movement of the bolt. The bolt catch may include a first external bolt catch portion that exits the first external wall portion of the receiver on the left side of the firearm and a second external bolt catch portion that exits the second external wall portion of the receiver on the right side of the firearm.

Abstract: A firearm with a lower receiver and bolt catch. The lower receiver may include a first external wall portion that is on the left side of the firearm and a second external wall portion on the right side of the firearm when a front of the lower receiver is facing forward, the rear of lower receiver is facing rearward, the bottom of the lower receiver is facing downward, and the firearm is in a firing position. The firearm may further include a bolt catch for preventing forward movement of the bolt. The bolt catch may include a first external bolt catch portion that exits the first external wall portion of the receiver on the left side of the firearm and a second external bolt catch portion that exits the second external wall portion of the receiver on the right side of the firearm.

Abstract: A barrel extension usable with a firearm and a firearm having a barrel extension is disclosed. The barrel extension may include a barrel extension body extending along a barrel extension central axis between a barrel interface end. The barrel interface end may be configured to be connected to a barrel and the bolt receiving end may be configured to selectively receive a rotatable bolt of the firearm. The barrel extension may further include a plurality of barrel extension lugs at the bolt receiving end having bolt lug receiving openings therebetween, wherein each of the plurality of barrel extension lugs has a lug inner surface that is a first distance from the central axis, and each of the plurality of receiving openings have a receiving opening inner surface that is a second distance from the central axis.

Abstract: A detachable Gas Key, which attaches to a Bolt Carrier, which provides gas to power the action of a semi automatic or select fire firearm. Improvements are made in both the attachment strength, as well as a significantly improved seal between the Gas Key and the Bolt Carrier.

Abstract: A bolt carrier group assembly and firearm containing a bolt carrier group assembly. The bolt carrier includes a first end closer to a front of the firearm and a second end closer to a rear end of the firearm and configured to slidably engage with a bolt. The bolt is configured to slide within the bolt carrier along a first axis and includes a plurality of lugs at a first end configured to engage with a corresponding plurality of lug receivers of the firearm, wherein the forward most edge of the plurality of lugs defines a bolt face of the bolt. The assembly further includes a cam pin operatively connected to the bolt and a cam slot within which the cam pin is constrained, wherein the cam pin travels along a path defined by the cam slot during rotational and translational movement of the bolt within the bolt carrier causing engagement and disengagement of the plurality of lugs and the lug receivers of the firearm.

Abstract: A bolt carrier for a firearm, including lugs on the first end to engage corresponding lugs of a barrel receiver/extension. The bolt carrier includes a cam slot within which a cam pin from a bolt is constrained to travel along a cam slot path during rotational and translational movement of the bolt. The cam slot defines (1) a first cam slot means for constraining motion of the cam pin and the bolt during engagement or disengagement of the lugs of the bolt and the corresponding lugs of the barrel receiver or extension; (2) a second cam slot means for imparting rotational movement to the cam pin and bolt during linear movement of the bolt carrier; and (3) a third cam slot means for constraining motion of the cam pin at an end of a rearward travel of the bolt and bolt carrier during an ejection cycle. The combination of the first, second, and third cam slot means yields an extension of the unlocking by over 10% and a delay of the actual unlock of the bolt by over 5% relative to TDP.

Abstract: A bolt carrier for a firearm, including lugs on the first end to engage corresponding lugs of a barrel receiver/extension. The bolt carrier includes a cam slot within which a cam pin from a bolt is constrained to travel along a cam slot path during rotational and translational movement of the bolt. The cam slot defines (1) a first cam slot means for constraining motion of the cam pin and the bolt during engagement or disengagement of the lugs of the bolt and the corresponding lugs of the barrel receiver or extension; (2) a second cam slot means for imparting rotational movement to the cam pin and bolt during linear movement of the bolt carrier; and (3) a third cam slot means for constraining motion of the cam pin at an end of a rearward travel of the bolt and bolt carrier during an ejection cycle. The combination of the first, second, and third cam slot means yields an extension of the unlocking by over 10% and a delay of the actual unlock of the bolt by over 5% relative to TDP.