A linear-to-rotary converter assembly includes a housing having a first portion, a second portion, and a bore in which a plunger is slidably disposed. The plunger includes a plunger body having threads and a plunger boss extending from the housing. At least one of a one-way bearing or a disk is disposed within the housing bore. A rod is disposed within the housing bore and has a first portion having threads engaging the plunger threads and a second portion extending through the at least one of the one-way bearing or the disk. At least one magnet is disposed within the housing adjacent to the one-way bearing or the disk. Linear movement of the plunger between a firing position and a recoil position rotates the rod and the one-way bearing or the disk in a first direction as the magnet acts on the at least one of the one-way bearing or the disk.

A firearm as disclosures herein comprises a main receiver body, a barrel, a breech bolt structure, a buffer assembly, a trigger group assembly, a bolt catch and at least one of an auto-sear, a magazine adapter and a breech bolt anti-rotation structure. The main receiver body is preferably of a monolithic construction whereby the handguard and breech bolt carrying bore can be manufactured from a single piece of material. The auto-sear is tripped by engagement with a buffer of the buffer assembly. The magazine adapter has an exterior surface structure engaged with a mating interior surface structure of a magazine well space of the main receiver body. A distal end portion of the breech bolt anti-rotation structure is engageable by the buffer for limiting forward travel of the buffer when the barrel is detached from the main receiver body.

A firearm as disclosures herein comprises a main receiver body, a barrel, a breech bolt structure, a buffer assembly, a trigger group assembly, a bolt catch and at least one of an auto-sear, a magazine adapter and a breech bolt anti-rotation structure. The main receiver body is preferably of a monolithic construction whereby the handguard and breech bolt carrying bore can be manufactured from a single piece of material. The auto-sear is tripped by engagement with a buffer of the buffer assembly. The magazine adapter has an exterior surface structure engaged with a mating interior surface structure of a magazine well space of the main receiver body. A distal end portion of the breech bolt anti-rotation structure is engageable by the buffer for limiting forward travel of the buffer when the barrel is detached from the main receiver body.

A buffer tube for a firearm can include a body defining an interior cavity for receiving a buffer spring, and a rail disposed on and/or formed from the outer surface of the body. The rail can include one or more pin holes configured to receive a pin of a stock to lock the stock in a position, and a trunk opening defined at an end of the rail forming a first rail sidewall and second rail sidewall configured to receive a trunk of an actuator. The first and/or second rail sidewalls can include a slot defined therethrough configured to receive a pin associated with the trunk of the actuator to linearly guide the actuator. The rail can include a slide bar channel defined through at least a portion of the rail and configured to allow a slide bar to slide therein relative to the one or more pin holes to urge a pin out of a respective pin hole and/or to block a pin from being received by the pin holes.

A buffer tube for a firearm can include a body defining an interior cavity for receiving a buffer spring, and a rail disposed on and/or formed from the outer surface of the body. The rail can include one or more pin holes configured to receive a pin of a stock to lock the stock in a position, and a trunk opening defined at an end of the rail forming a first rail sidewall and second rail sidewall configured to receive a trunk of an actuator. The first and/or second rail sidewalls can include a slot defined therethrough configured to receive a pin associated with the trunk of the actuator to linearly guide the actuator. The rail can include a slide bar channel defined through at least a portion of the rail and configured to allow a slide bar to slide therein relative to the one or more pin holes to urge a pin out of a respective pin hole and/or to block a pin from being received by the pin holes.

A firearm buffer includes a buffer casing having a casing chamber with open and closed ends, and buffer weight within the casing chamber. A buffer plug is received in the open end of the buffer casing. A cross pin extends through at least a portion of the buffer plug retaining the buffer plug on the buffer casing. A locking pin is longitudinally displaceable between a first position and a second position. In the first position, the locking pin is engaged with the cross pin and retains the cross pin in position with respect to the buffer plug. In the second position, the locking pin is disengaged from the cross pin such that the cross pin is removable from engagement with the buffer plug thereby permitting disassembly of the firearm buffer. A method of assembling a firearm buffer is also included.

The invention is related to the removable connection of the carrier tube (1) and the components on it to the plastic receiver (7) by means of the fixing nut (2) in a combination of a carrier tube (1) and plastic receiver (7). It is related to positioning of recoil spring inside the carrier tube (1) and the plastic receiver (7) made of plastic material in which more than one stock with different types and features can be located on the same carrier tube.

The invention is related to the removable connection of the carrier tube (1) and the components on it to the plastic receiver (7) by means of the fixing nut (2) in a combination of a carrier tube (1) and plastic receiver (7). It is related to positioning of recoil spring inside the carrier tube (1) and the plastic receiver (7) made of plastic material in which more than one stock with different types and features can be located on the same carrier tube.

A compact stock for an AR-style firearm includes a receiver extension configured to attach to a lower receiver of the firearm, a buffer assembly receivable in the receiver extension, a buffer biasing member receivable in the receiver extension, and a buffer locking mechanism. The buffer assembly is configured to reciprocate between a retracted position wherein the buffer assembly is contained within the receiver extension and an extended position wherein the buffer assembly is in-battery within an upper receiver of the firearm. The buffer biasing member is configured to bias the buffer assembly toward the extended position. The buffer locking mechanism is configured to selectably retain the buffer assembly and the buffer biasing member within the receiver extension when the buffer assembly is in the retracted position such that the upper receiver is rotatable relative to the lower receiver about a forward take down pin of the firearm unimpeded by the buffer assembly and buffer biasing member.

A compact stock for an AR-style firearm includes a receiver extension configured to attach to a lower receiver of the firearm, a buffer assembly receivable in the receiver extension, a buffer biasing member receivable in the receiver extension, and a buffer locking mechanism. The buffer assembly is configured to reciprocate between a retracted position wherein the buffer assembly is contained within the receiver extension and an extended position wherein the buffer assembly is in-battery within an upper receiver of the firearm. The buffer biasing member is configured to bias the buffer assembly toward the extended position. The buffer locking mechanism is configured to selectably retain the buffer assembly and the buffer biasing member within the receiver extension when the buffer assembly is in the retracted position such that the upper receiver is rotatable relative to the lower receiver about a forward take down pin of the firearm unimpeded by the buffer assembly and buffer biasing member.