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 using blowback action has a barrel which is movably mounted within a shroud which is fixedly mounted on the firearm's frame. A gas space is formed between the barrel and the shroud by a difference between the inner diameter of the shroud and the outer diameter of the barrel. At least one gas port provides fluid communication between the bore of the barrel and the gas space. During firing of a cartridge, pressurized gas in the gas space applies a force to the barrel which moves relatively to the shroud away from the muzzle end of the firearm to engage a slide or bolt, helping to move it out of battery and extract the spent cartridge casing. Gas is vented to the atmosphere through a gas vent defined between the barrel and the shroud in fluid communication with the gas space.

A firearm using blowback action has a barrel which is movably mounted within a shroud which is fixedly mounted on the firearm's frame. A gas space is formed between the barrel and the shroud by a difference between the inner diameter of the shroud and the outer diameter of the barrel. At least one gas port provides fluid communication between the bore of the barrel and the gas space. During firing of a cartridge, pressurized gas in the gas space applies a force to the barrel which moves relatively to the shroud away from the muzzle end of the firearm to engage a slide or bolt, helping to move it out of battery and extract the spent cartridge casing. Gas is vented to the atmosphere through a gas vent defined between the barrel and the shroud in fluid communication with the gas space.

Firearms with gas piston assemblies have a receiver defining a passage receiving a reciprocating bolt assembly, a barrel defining a barrel axis and extending from the receiver in a forward direction and defining a barrel gas aperture, a gas block connected to the barrel and defining a piston bore in communication with the gas block bore, a piston assembly having a forward end operably engaged to the piston bore and a rear end operably engaged to the reciprocating bolt assembly, the piston assembly having a piston closely received in the piston bore and having a piston rear end, the piston assembly including an elongated intermediate rod having an intermediate rod forward end registered with the piston rear end and an intermediate rod rear end, and the piston assembly including a rear portion having a forward end registered with the intermediate rod rear end and a rear portion.

A modified AK-style rifle including a receiver body with a back end having a first threaded cylindrical cavity and a second cylindrical cavity located below the first threaded cylindrical cavity. A lower portion below the first threaded cylindrical cavity has a width that is narrower than the upper receiver section to allow for passage of a pair of parallel and opposing telescoping bars on each side. A trunnion is connected to the receiver front end and an ambidextrous bolt stop is attached to the receiver body. A removable stock is coupled to the first threaded cylindrical cavity. A first bolt carrier rail is attached to a first side wall of the receiver body and a second bolt carrier rail is attached to a second side wall of the receiver body. A bolt carrier slidingly bears on the first bolt carrier rail and the second bolt carrier rail. A gas block includes a short stroke gas piston aligned with the bolt carrier section.

A modified AK-style rifle including a receiver body with a back end having a first threaded cylindrical cavity and a second cylindrical cavity located below the first threaded cylindrical cavity. A lower portion below the first threaded cylindrical cavity has a width that is narrower than the upper receiver section to allow for passage of a pair of parallel and opposing telescoping bars on each side. A trunnion is connected to the receiver front end and an ambidextrous bolt stop is attached to the receiver body. A removable stock is coupled to the first threaded cylindrical cavity. A first bolt carrier rail is attached to a first side wall of the receiver body and a second bolt carrier rail is attached to a second side wall of the receiver body. A bolt carrier slidingly bears on the first bolt carrier rail and the second bolt carrier rail. A gas block includes a short stroke gas piston aligned with the bolt carrier section.

Disclosed herein is a modified rifle bolt carrier allowing a selectively openable vent/valve at the location where exhaust gas is pressurizing the bolt carrier to control carrier speed under suppressed fire in a first valve position or unsuppressed fire in a second valve position. A valve core is disclosed which may be rotated 180° to a first “open” setting for non-suppressed fire from its position in a “closed” position for suppressed fire, and a third “median” position. The modified bolt carrier will allow an operator of the firearm to adjust for a suppressor without changing the gas block or having to modify or adapt the front end or barrel end of the firearm.

A gas tube support system for a gas-actuated firearm contains an annular or bored housing for receipt of a gas tube therein, thereby securing the gas tube during operation of the firearm. At least one or more bores are drilled or formed within the annular or bored housing to provide an impingement of the gas tube as it extends through the annular or bored housing. One or more fasteners are threadedly or otherwise received within a corresponding one of one or more respective bores, thereby securing the gas tube within the annular or bored housing. A gas-actuated firearm containing the gas tube support system is also provided.

A gas tube support system for a gas-actuated firearm contains an annular or bored housing for receipt of a gas tube therein, thereby securing the gas tube during operation of the firearm. At least one or more bores are drilled or formed within the annular or bored housing to provide an impingement of the gas tube as it extends through the annular or bored housing. One or more fasteners are threadedly or otherwise received within a corresponding one of one or more respective bores, thereby securing the gas tube within the annular or bored housing. A gas-actuated firearm containing the gas tube support system is also provided.