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. The bolt catch may further include an internal bolt catch portion within the lower receiver that connects the first external bolt catch portion and the second external bolt catch portion, wherein at least a first portion of the internal bolt catch portion extends in at least one of a rearward direction towards the rear of the receiver, or a downward direction towards the bottom of the lower receiver.

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. The bolt catch may further include an internal bolt catch portion within the lower receiver that connects the first external bolt catch portion and the second external bolt catch portion, wherein at least a first portion of the internal bolt catch portion extends in at least one of a rearward direction towards the rear of the receiver, or a downward direction towards the bottom of the lower receiver.

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. The bolt catch may further include an internal bolt catch portion within the lower receiver that connects the first external bolt catch portion and the second external bolt catch portion, wherein at least a first portion of the internal bolt catch portion extends in at least one of a rearward direction towards the rear of the receiver, or a downward direction towards the bottom of the lower receiver.

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. The bolt catch may further include an internal bolt catch portion within the lower receiver that connects the first external bolt catch portion and the second external bolt catch portion, wherein at least a first portion of the internal bolt catch portion extends in at least one of a rearward direction towards the rear of the receiver, or a downward direction towards the bottom of the lower receiver.

Disclosed herein is a rotary lockup action including a firing mechanism for a firearm. The firearm including a receiver having a cavity therein configured to accept the firing mechanism. The firing mechanism comprising a bolt guide rail fixed to the inner surface of the cavity of the receiver. The firing mechanism also comprises a bolt sliding along a longitudinal axis on the bolt guide rail. Also disclosed is a change handle rotatably mounted to the bolt so as to rotate relative thereto about a vertical axis orthogonal to the longitudinal axis. The charge handle may be mounted to the bolt so as to longitudinally reposition therewith. The charge handle having a surface defining a cut therein aligned with a slot in the bolt when the bolt is in a rearward position; and wherein the surface defining a cut in the charge handle is not aligned with the slot in the bolt when the bolt is in a forward positon.

Disclosed herein is a rotary lockup action including a firing mechanism for a firearm. The firearm including a receiver having a cavity therein configured to accept the firing mechanism. The firing mechanism comprising a bolt guide rail fixed to the inner surface of the cavity of the receiver. The firing mechanism also comprises a bolt sliding along a longitudinal axis on the bolt guide rail. Also disclosed is a change handle rotatably mounted to the bolt so as to rotate relative thereto about a vertical axis orthogonal to the longitudinal axis. The charge handle may be mounted to the bolt so as to longitudinally reposition therewith. The charge handle having a surface defining a cut therein aligned with a slot in the bolt when the bolt is in a rearward position; and wherein the surface defining a cut in the charge handle is not aligned with the slot in the bolt when the bolt is in a forward positon.

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. The bolt catch may further include an internal bolt catch portion within the lower receiver that connects the first external bolt catch portion and the second external bolt catch portion, wherein at least a first portion of the internal bolt catch portion extends in at least one of a rearward direction towards the rear of the receiver, or a downward direction towards the bottom of the lower receiver.

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. The bolt catch may further include an internal bolt catch portion within the lower receiver that connects the first external bolt catch portion and the second external bolt catch portion, wherein at least a first portion of the internal bolt catch portion extends in at least one of a rearward direction towards the rear of the receiver, or a downward direction towards the bottom of the lower receiver.

A firearm system includes a bolt carrier with an internal cavity, a piston disposed within the internal cavity, a forward configuration where the piston is in a forwardmost position relative to the bolt carrier, and an aft configuration where the piston is in a rearmost position relative to the bolt carrier. The piston slides forward and aft relative to the bolt carrier. In the forward configuration, the entire piston remains disposed within the bolt carrier.

A firearm system includes a bolt carrier with an internal cavity, a piston disposed within the internal cavity, a forward configuration where the piston is in a forwardmost position relative to the bolt carrier, and an aft configuration where the piston is in a rearmost position relative to the bolt carrier. The piston slides forward and aft relative to the bolt carrier. In the forward configuration, the entire piston remains disposed within the bolt carrier.