Abstract: Disclosed herein are bolt carrier movement mechanisms that offer a higher ratio of bolt carrier applied force to user applied bolt action operating force. Such bolt carrier movement mechanism may comprise a bolt carrier, an impingement body, a primary extraction leverage member, and an action control structure coupler. The impingement body has at least one impingement surface. The primary extraction leverage member has a coupler mounting portion, an impingement member portion, and a bolt carrier mounting portion. The primary extraction leverage member is engaged at the bolt carrier mounting portion of the bolt carrier. The impingement member portion of the primary extraction leverage member is adjacent to the at least one impingement surface of the impingement body and includes at least one impingement member. The action control structure coupler is pivotably engaged with the coupler mounting portion of the primary extraction leverage member.

Abstract: A receiver system comprises upper and lower receiver bodies, a lower receiver body, a bolt carrier, and an action-control lever. The upper receiver body is a semi-automatic firearm upper receiver body. The lower receiver body includes a stock mounting flange having a stock receptacle that is matingly engageable with a receiver engaging portion of a stock. The bolt carrier is slidably disposed within a bolt carrier receiving bore of the upper receiver body. The action-control lever has a hand loop and a first attachment arm having a proximate end portion thereof attached to the hand loop. The first attachment arm is pivotably attached at a distal end thereof to the lower receiver body for being pivoted between a battery-ready position and a cartridge-ejecting position relative to the lower receiver body. The action-control lever is attached to the bolt carrier through an articulating coupling assembly.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A firearm preferably permits a user to readily change ammunition type and associated magazine configuration at user discretion. Such a firearm may be optimally practiced as a pistol, rifle, or submachine gun but is not limited to a particular caliber size or configurations. A main receiver body of the firearm is preferably of a monolithic construction whereby the handguard and breech bolt carrying bore can be manufactured from a single piece of material such as, for example, an aluminum extrusion or polymer injection molded component. In at least one or more of these respects, the firearm is of an improved design to both simplify and speed manufacturing and assembly, while simultaneously reducing manufacturing costs normally associated with the firearm industry's usual state-of-the-art (e.g., prior art) methods.

Abstract: A rifle kit comprises a rifle receiver structure having a central passage configured for having a substantially as-manufactured breech bolt of a pistol mounted therein and has one or more shoulder stock mounting portions configured for having a shoulder stock structure engaged therewith. A substantially as-manufactured breech bolt of the kit is configured by an original equipment manufacturer (OEM) thereof for being mounted on a pistol receiver body configured by the OEM. The rifle barrel is mountable within the central passage of the rifle receiver structure. A chamber end portion of the rifle barrel is configured for engaging a mating portion of the substantially as-manufactured breech bolt. A shoulder stock structure of the kit includes a receiver structure engaging portion configured for allowing the shoulder stock structure to be mounted on the rifle receiver structure exclusively through engagement with the one or more stock mounting portions of the rifle receiver structure.

Abstract: A firearm receiver apparatus comprises a receiver body and a light emitting device. The receiver body includes a bolt carrier bore and a cartridge ejection port. The bolt carrier bore extends between first and second end portions of the receiver body. The cartridge ejection port extends through a sidewall of the receiver body and intersects the bolt carrier bore. The light emitting device is attached to the sidewall in a manner for causing at least a portion of a beam of light emitted therefrom to be directed through the cartridge ejection port into the bolt carrier bore.