Abstract: To permit ease and efficiency for the extraction of spent cartridge cases from the cartridge chamber of a firearm barrel within a wide range of temperature conditions, the internal tapered surface of the body region of a cartridge chamber is prepared by establishing circumferentially spaced longitudinal straight or curved regions of the internal surface finish to create an internal cartridge chamber geometry having gradually tapered spaced longitudinally relieved linear or spiral areas having longitudinal linear or spiral lands between each of the relieved areas. The circumferentially spaced lands develop controlled impedance to rearward cartridge case movement on cartridge firing to effectively protect the bolt and extractor mechanisms of the firearm against early failure.

Abstract: A tactical firearm having upper and lower receivers that are releasably connected. A cartridge gas energized bolt carrier assembly is moveable within the upper receiver and is provided with anti-tilt guidance with respect to a spring energized buffer mechanism, that is provided within a butt-stock of the lower receiver. The bolt carrier assembly moves a cartridge from a magazine and feeds the cartridge into the cartridge chamber of the barrel and returns the bolt carrier assembly to its closed and locked condition upon dissipation of the cartridge gas energizing force. The bolt carrier assembly is efficiently guided to prevent its misalignment during its rearward and forward auto-loading movement.

Abstract: A free-standing post supported target mechanism has a support post of a defined cross-sectional geometry. A baseplate defines a post opening receiving the support post and has a first orientation permitting movement of the baseplate along the length of the support post and a second orientation establishing a gripping relation with the support post. A spall plate defines a post opening receiving the support post and has a first orientation permitting movement of the spall plate along the length of the support post and a second orientation establishing a gripping relation of the spall plate with the support post. A target plate engages the baseplate and the spall plate and is secured by a locking member. A target base defines a receptacle receiving and supporting the support post and establishes a weight-forward condition that offsets the rearward forces of bullet impact.

Abstract: A pivot mount base is assembled to or removed from the sight mounting rail of a firearm by a lever actuated cam energized rail clamping mechanism. A pivot shaft is fixed within an axially oriented pivot passage of the mount base and defines spaced external bearing surfaces. A pivotal accessory support device defines spaced pivot receptacles having a portion of said pivot mount base located therebetween and has bearing receptacles receiving the pivot shaft. The accessory support device is moveable both linearly and rotatably relative to the fixed pivot shaft and is urged toward a locked position with a locking pin by a compression spring and is moved against the spring force to free the accessory support device for manual rotational movement to a precision aiming position and to a laterally offset position.

Abstract: A suppressor mechanism has an elongate tubular housing containing baffles and into which is assembled a suppressor mount body having spaced thread sections and spaced tapered gas seal surfaces. An adapter/muzzle brake member defines an internally threaded section that establishes threaded connection with the reduced diameter externally threaded section of a typical firearm barrel that is prepared for attachment of a suppressor thereto. The suppressor mount body and the muzzle brake/adapter member each define spaced threaded sections that establish threaded connection and promote enhanced structural integrity. The spaced internal tapered surfaces of the suppressor mount body and the spaced external tapered surfaces of the muzzle brake/adapter member establish spaced internal cartridge gas seals that prevent high pressure hot cartridge gas and gunpowder residue from coming into contact with and potentially fouling the thread connections of the suppressor mount body and the muzzle brake/adapter member.

Abstract: A free-standing post supported target mechanism has a support post of a defined cross-sectional geometry. A baseplate defines a post opening receiving the support post and has a first orientation permitting movement of the baseplate along the length of the support post and a second orientation establishing a gripping relation with the support post. A spall plate defines a post opening receiving the support post and has a first orientation permitting movement of the spall plate along the length of the support post and a second orientation establishing a gripping relation of the spall plate with the support post. A target plate engages the baseplate and the spall plate and is secured by a locking member. A target base defines a receptacle receiving and supporting the support post and establishes a weight-forward condition that offsets the rearward forces of bullet impact.

Abstract: A firearm has a receiver extension defining a plurality of spaced butt-stock positioning receptacles. A butt-stock has a locking pin that is moveable into one of the receptacles for locking the butt-stock at a desired position on the receiver extension. A lock pin actuator is manually moveable by applying a force to a pull ring member to cause retraction of the locking pin from a butt-stock positioning receptacle in preparation for position adjustment or removal of the butt-stock relative to the receiver extension. A rotary knob lock positioning member is rotatable to locked and unlocked positions and when locked ensures against complete separation of the butt-stock from the receiver extension member upon maximum length adjustment of the butt-stock.

Abstract: A sight mount for firearms having short sight mount blocks and having sheet metal receiver covers. A mount base is pivotally connected with the sight mount block and has a sight support platform that is positioned above the receiver cover and provides support for an optical sighting device. A lock member has releasable locking engagement with the lock retainer members and having a portion thereof engaging the rear sight block and securing said mount base against movement from said sighting position. A rear sight member is defined by an upturned portion of the lock member and has a sighting notch that is visible in co-witnessing relation when viewing through the optical sighting device.

Abstract: A cartridge gas port selector mechanism for a firearm barrel having a plurality of gas ports extending from the barrel bore and having a gas block with gas passages in communication with a gas tube. A selector valve member is movable within the gas block between an open condition permitting flow of cartridge gas from one or more ports of the firearm barrel to the cartridge gas passage and a closed condition blocking flow of cartridge gas from the barrel bore to the cartridge gas passage. A valve selector or actuator is connected with the valve member and is selectively moveable to position the valve member at the open condition or the closed condition to select the volume and timing of cartridge gas communication from the barrel bore to the gas energized autoloading mechanism of the firearm.

Abstract: A pivot mount base is assembled to or removed from the sight mounting rail of a firearm by a lever actuated cam energized rail clamping mechanism. A pivot shaft is fixed within an axially oriented pivot passage of the mount base and defines spaced external bearing surfaces. A pivotal accessory support device defines spaced pivot receptacles having a portion of said pivot mount base located therebetween and has bearing receptacles receiving the pivot shaft. The accessory support device is moveable both linearly and rotatably relative to the fixed pivot shaft and is urged toward a locked position with a locking pin by a compression spring and is moved against the spring force to free the accessory support device for manual rotational movement to a precision aiming position and to a laterally offset position.

Abstract: A method for and apparatus absorbing the energy of a projectile strike by a multiplicity of energy dissipating elements of high mass that are contained within a spaced defined by walls. A projectile passing through one of the walls transmits its energy to a multiplicity of energy dissipating elements, such as hardened steel balls or various shaped objects of high mass, by causing energy transfer and distribution through a loose mass of the energy dissipating elements and disintegrating the projectiles. Energy absorbing apparatus embodying this method may take the form of a static or moveable bullet or projectile trap, an energy absorbing external barrier or shelter on vehicles, and portable personnel protection structures for use in a tactical environment. The energy absorbing and dissipating elements are subject to some movement in response to the energy imparted by the projectiles and quickly settle after the energy has been dissipated.

Abstract: A method and apparatus for dampening vibration forces being transmitted from a vehicle to a firearm mount and firearm to permit substantially vibration free aiming and firing of the firearm from the moving vehicle. A support member supports a pliable membrane and permits flexing movement of a region of the membrane in response to vibration forces. A firearm mount is secured to a flexing region of the membrane. Vibration forces transmitted from the vehicle to the firearm mount are dampened by flexing of the membrane due to the mass of the firearm thereby permitting the firearm to remain stabilized for accurate aiming and firing.

Abstract: A sight mount base having longitudinally spaced base sections defines an intermediate space or recess within which the downwardly facing Horus reticle adjustment knob of an inverted optical sighting device is received. The sight mount base may have independent, spaced base sections, each being releasably mounted to the accessory mount rail of the firearm or may be a unitary base structure machined to define an intermediate recess or receptacle within which the Horus reticle adjustment knob is received. The spaced base sections may be interconnected by a structural bridge so that the sight mount base is in the form of an integral structure. Inverted positioning of the optical sighting device eliminates the presence of upwardly projecting obstructions.

Abstract: A cartridge gas port selector mechanism for a firearm barrel having a plurality of gas ports extending from the barrel bore and having a gas block with gas passages in communication with a gas tube. A selector valve member is movable within the gas block between an open condition permitting flow of cartridge gas from one or more ports of the firearm barrel to the cartridge gas passage and a closed condition blocking flow of cartridge gas from the barrel bore to the cartridge gas passage. A valve selector or actuator is connected with the valve member and is selectively moveable to position the valve member at the open condition or the closed condition to select the volume and timing of cartridge gas communication from the barrel bore to the gas energized autoloading mechanism of the firearm.

Abstract: A suppressor mechanism has an elongate tubular housing containing baffles and into which is assembled a suppressor mount body having spaced thread sections and spaced tapered gas seal surfaces. An adapter/muzzle brake member defines an internally threaded section that establishes threaded connection with the reduced diameter externally threaded section of a typical firearm barrel that is prepared for attachment of a suppressor thereto. The suppressor mount body and the muzzle brake/adapter member each define spaced threaded sections that establish threaded connection and promote enhanced structural integrity. The spaced internal tapered surfaces of the suppressor mount body and the spaced external tapered surfaces of the muzzle brake/adapter member establish spaced internal cartridge gas seals that prevent high pressure hot cartridge gas and gunpowder residue from coming into contact with and potentially fouling the thread connections of the suppressor mount body and the muzzle brake/adapter member.

Abstract: A cartridge magazine for firearms having internal lateral guide ridges of dimensions for establishing lateral guiding engagement with cartridges within the magazine chamber and having longitudinal internal guide ridges projecting inwardly from said side panels. The internal longitudinal guide ridges establish low friction essentially line contact with the uppermost cartridge and establish low friction forward charging movement of the uppermost cartridge from the cartridge magazine during firearm loading. The cartridge magazine is preferably formed from a single piece of sheet metal stock and is die folded and die formed to define external depressions and internal low friction cartridge guide ridges for lateral guiding of cartridge movement within the magazine and forward guiding movement of cartridges as they are dispensed from the magazine.

Abstract: A mounting base mechanism for releasably securing an accessory device to a mechanical structure having opposed oppositely angulated clamp surfaces. The mounting base mechanism defines a first clamp surface having clamping engagement with one of the angulated clamp surfaces. A clamp support structure projects laterally from the mounting base mechanism and provides support for a clamp actuating mechanism having a clamping plate. A retainer device supported by the clamp support structure is operative to move the clamping plate substantially linearly for clamping engagement of the clamp plate with the other of the oppositely angulated clamp surfaces. A keeper member prevents inadvertent separation of the retainer and clamping plate from the clamp support structure.

Abstract: A mounting base mechanism for releasably securing an accessory device to a mechanical structure having opposed oppositely angulated clamp surfaces. The mounting base mechanism defines a first clamp surface having clamping engagement with one of the angulated clamp surfaces. A clamp support structure projects laterally from the mounting base mechanism and provides support for a clamp actuating mechanism having a clamping plate. A retainer device supported by the clamp support structure is operative to move the clamping plate substantially linerally for clamping engagement of the clamp plate with the other of the oppositely angulated clamp surfaces. A keeper member prevents inadvertent separation of the retainer and clamping plate from the clamp support structure.

Abstract: A cheek riser mechanism has a mounting base or saddle that is adapted for mounting to a gun-stock and defines guide rail members. A movable cheek riser member has guide grooves that receive the guide rail members and is linearly movable along the length of the guide rails. Upon rearward movement of the charging handle of an AR15 type rifle the movable cheek riser can be engaged and moved rearwardly by the user's hand or by the charging handle so that it does not interfere with a cartridge charging operation. A riser spring is compressed during rearward movement of the cheek riser and returns the movable cheek riser to its use position upon release of the charging handle.

Abstract: A hand-guard and barrel nut clamping assembly for tactical firearms and other mechanical equipment that is subject to frequent or sustained vibration or shock, such as when a firearm is subjected to sustained rapid fire and/or the firearm is handled roughly. A small generally half-moon shaped anti-rotation clamping member is secured to a hand-guard support element or other suitable structure by socket head cap screws and is secured in frictional contact with components of the hand-guard mount and a barrel nut. The anti-rotation clamping member functions as a key to “tie” the barrel nut and hand-guard nut together, simultaneously preventing either one from rotating, and thus preventing inadvertent vibration or shock induced loosening of either the hand-guard retainer nut or the barrel nut. The anti-rotation clamping member is also keyed onto the front of the upper receiver by a slot into which a portion of the receiver is engaged.