Abstract: 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.

Abstract: 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.

Abstract: A magazine safety for a semiautomatic firearm uses two levers connected via a floating pin. The first lever is pivotable into and out of the magazine well. The second lever is spring biased to position a spur extending therefrom into the path of a trigger bar. An end of the second lever is connected to the first lever via the floating pin. In the absence of the magazine from the magazine well the first lever will rotate into the magazine well, thereby permitting the second lever to rotate and position the spur in the path of the trigger bar to prevent discharge of the firearm.

Abstract: A grip strap is removably attachable to a grip of a firearm using a plunger mounted in the grip and biased by a mainspring which also biases a hammer strut of the firearm.

Abstract: A magazine safety for a semiautomatic firearm uses two levers connected via a floating pin. The first lever is pivotable into and out of the magazine well. The second lever is spring biased to position a spur extending therefrom into the path of a trigger bar. An end of the second lever is connected to the first lever via the floating pin. In the absence of the magazine from the magazine well the first lever will rotate into the magazine well, thereby permitting the second lever to rotate and position the spur in the path of the trigger bar to prevent discharge of the firearm.

Abstract: A grip strap is removably attachable to a grip of a firearm using a plunger mounted in the grip and biased by a mainspring which also biases a hammer strut of the firearm.

Abstract: An ammunition magazine for semiautomatic firearms has an opening at the end of a tube which is offset from the geometric center of the tube cross section and which is skewed about an axis extending lengthwise along the tube and through the geometrical center. Offset and skew of the opening are achieved by asymmetrically positioning the feed lips defining the opening relatively to the axis as well as angularly orienting the lips relatively to the bore of the tube.

Abstract: A disconnector for pistols having a trigger bar uses a body rotatably mounted on the pistol frame to permit or prevent engagement between the trigger bar and the pistol's sear. The body has a plurality of surfaces, one of which engages the trigger bar and pivots it between a safe orientation, out of alignment with the pistol's sear, and a fire orientation, aligned with the sear, when the body rotates between a safe position and a fire position. Another body surface engages the slide, the body being rotated into the safe position when the slide is out of battery. Another surface engages a grip safety and another surface engages a manual safety. Both safeties effect rotation of the body between the safe and fire positions when they are actuated.

Abstract: A captive recoil spring assembly includes a guide rod surrounded by a coil spring. The spring is captured between a base at one end of the guide rod, and a body at its opposite end. The body is shaped to engage the spring at one or more sectors, leaving one or more remaining sectors free to engage the slide. Use of such a body permits a round wire spring to be used without the need for close dimensional tolerances on the engaging parts.

Abstract: A disconnector for pistols having a trigger bar uses a body rotatably mounted on the pistol frame to permit or prevent engagement between the trigger bar and the pistol's sear. The body has a plurality of surfaces, one of which engages the trigger bar and pivots it between a safe orientation, out of alignment with the pistol's sear, and a fire orientation, aligned with the sear, when the body rotates between a safe position and a fire position. Another body surface engages the slide, the body being rotated into the safe position when the slide is out of battery. Another surface engages a grip safety and another surface engages a manual safety. Both safeties effect rotation of the body between the safe and fire positions when they are actuated.

Abstract: A pistol has a bolt with a surface that contacts the cartridge in the magazine to next be chambered. The bolt is mounted within the slide. As the bolt moves with the slide out of battery the surface exerts a force on the cartridge in the direction of motion of the slide. The force counteracts inertial forces on the cartridge imposed by recoil of the pistol.

Abstract: A captive recoil spring assembly includes a guide rod surrounded by a coil spring. The spring is captured between a base at one end of the guide rod, and a body at its opposite end. The body is shaped to engage the spring at one or more sectors, leaving one or more remaining sectors free to engage the slide. Use of such a body permits a round wire spring to be used without the need for close dimensional tolerances on the engaging parts.

Abstract: A pistol has a bolt with a surface that contacts the cartridge in the magazine to next be chambered. The bolt is mounted within the slide. As the bolt moves with the slide out of battery the surface exerts a force on the cartridge in the direction of motion of the slide. The force counteracts inertial forces on the cartridge imposed by recoil of the pistol.

Abstract: A sight for a pistol has a sliding fit within a channel in the slide of the pistol. A fastener retains the sight to the slide. The fastener passes through a slot in the slide. The slot is surrounded by a countersink surface and has a major dimension oriented transversely to the longitudinal axis of the slide. The fastener has a conical head with a cone angle which may be the same as or different from the angle of the countersink surface.

Abstract: A firearm includes a frame having at least one interior receptacle defined by opposed interior walls and having opposed guide rails extending from the opposed interior walls, and at least one modular housing disposed in the receptacle and accommodating at least one operational component of the firearm. The modular housing is defined by opposed sidewalls having opposed guide channels formed therein, the guide channels being configured to selectively engage the guide rails to facilitate the aligning of the modular housing with respect to the interior receptacle. The at least one operational component and the modular housing are pre-assembled together as an integrated unit for drop-in insertion into the receptacle during assembly of the firearm.

Abstract: An extractor is mounted on a slide of an auto-loading firearm. The extractor is capable of rotational and translational motion relative to the slide resulting in improved functioning through an increase in flag distance and reduced friction between the extractor and cartridge when the slide moves into battery. The extractor has a cam follower which cooperates with a cam on the slide to maintain the extractor hook in engagement with the rim of the cartridge during extraction. The extractor is biased into engagement with the cam, and a second cam follower on the extractor is engageable with the barrel face when the slide moves into battery.

Abstract: A firearm has a magazine safety and a take-down mechanism. The magazine safety operates in conjunction with a trigger bar and a disconnect bar. The magazine safety has a safety arm which moves the disconnect bar out of engagement with the trigger bar when a magazine is inserted. This permits the trigger bar to engage the sear. When the magazine is removed, the safety arm disengages from the disconnect bar, permitting the disconnect bar to move the trigger bar into a position where it cannot engage the sear. The safety bar also operates as a take-down mechanism. When moved to a take-down position, the safety arm engages and moves the sear into a position where it cannot engage the striker so as to permit removal of the slide carrying the striker from the firearm.