An assembly for a modular, compact firearm includes a universal action and an interchangeable, non-reciprocating barrel. The barrel may directly mount various optical sighting systems and provide integral muzzle compensation and sound suppression capabilities. The firearm utilizes a universal action comprised of a slide assembly, breechblock assembly, recoil assembly, and receiver which mounts a variety of barrel assemblies and assembles into a variety of different grip frames. The action of the firearm utilizes a partially-locked breechblock which amplifies the inertia of a slide.

A firearm optical sight adapter is disclosed. The optical sight adapter can include an adapter plate with first and second opposing mounting surfaces, and a registration pin extending orthogonally from the first mounting surface. The optical sight adapter may further include a socket having a recess extending from the second mounting surface to a bottom wall intermediate between the first and mounting surfaces and an aperture extending from the bottom wall of the recess through the first mounting surface along a first longitudinal axis. A removable mounting post can be configured to engage in the socket. The optical sight adapter may include a recoil buffer extending upright from the first surface.

Provided is a frame assembly for a pistol. The frame assembly includes a lower frame having a grip formed at a lower side and an upper frame that is assembled on the lower frame and is assembled to a slide. The lower frame has a mounting projection which has a predetermined length and projects upward to a predetermined height in a direction to face the upper frame. The upper frame has a mounting groove which has a predetermined depth and into which the mounting projection is inserted in a direction to face the lower frame. The lower frame and the upper frame are assembled together by a screw which is fastened to penetrate the mounting groove and the mounting projection in this order from an inner side of the upper frame.

A weapon includes a stationary barrel mounted fixedly in a frame, and a slide movably mounted to the frame for forward and backward displacement relative to the frame. A locking mechanism for the slide includes a retractable spring acting on the slide in a direction towards a forward-most position of the slide, and a pair of levers arranged under the barrel between the slide and the frame. The pair of have opposite end axes of rotation and are mutually rotatably connected by a common axis. The common axis lies under a line that extends between the end axes of rotation of the pair of levers.

A suppressed pistol has a breech block and a slide mounted on a frame. The breech block and slide are separate pieces, movable relatively to one another and the frame. A link extends between the breech block and the frame. The link carries a cam and a cam follower. The cam follower on the link engages a cam on the frame, the cam on the link engages a cam follower on the slide. Action between the cams, cam followers and the link causes separation between the breech block and the slide during operation of the pistol. The suppressor includes a container having baffle plates with truncated cones defining openings offset from the geometric centers of the baffle plates.

A trigger activated arm may use a piston moving within a cylinder to dampen gun bolt speed. In some embodiments, gun bolt motion increases pressure within the cylinder bore to dampen rearward gun bolt speed. The pressure may be high enough to unseat the cylinder creating a vent that cylinder fluid exits. In other embodiments, gun bolt motion decreases pressure within the cylinder bore to dampen forward gun bolt speed.

A trigger activated arm may use a piston moving within a cylinder to dampen gun bolt speed. In some embodiments, gun bolt motion increases pressure within the cylinder bore to dampen rearward gun bolt speed. The pressure may be high enough to unseat the cylinder creating a vent that cylinder fluid exits. In other embodiments, gun bolt motion decreases pressure within the cylinder bore to dampen forward gun bolt speed.

An apparatus and method for modifying a handgun to accept an optical sight comprises and modified slide mechanism adapted to include a flat recessed rear section configured to receive an adapter plate for mounting an optical sight. Various embodiments of the adapter include modified internal components used to replace stock components what will no longer fit within the modified profile of the slide mechanism. Replacement of the slide mechanism and associated internal components will allow a user to add an optical sight to an existing handgun.

A slide assembly for a firearm comprising a slide and an extractor assembly is provided. The slide includes a mounting recess about a top side of the slide, and a housing recess about a proximal end of the slide. The extractor assembly is mounted within the housing recess and includes a distal end for engaging a cartridge and a proximal end opposite the distal end. The proximal end terminates at a position adjacent about a mid-portion of the mounting recess. One or more retaining holes are provided within a proximal region of the mounting recess spaced from the proximal end of the extractor assembly. Firearm sights are attachable to the mounting recess via fasteners engaging the retaining holes. The retaining holes are arranged such that they do not interfere with the extractor assembly or other components within the housing recess of the slide.

Various embodiments for an angled action firearm that counteracts muzzle rise are described. The angled action firearm includes a receiver having a first receiver end and a second receiver end. The receiver has a top surface sloping upwards from the first receiver end to the second receiver end. The angled action firearm further includes a slide moveably coupled to the receiver having a bottom surface opposite that of the top surface of the receiver. The slide has a first slide end and a second slide end, where the angled bottom surface of the slide slopes upward from the first slide end to the second slide end. The angled action of the slide causes downward pressure during recoil counteracting muzzle rise.