Frame construction for a firearm (10) with a frame (18) and a slide (12) constrained to move longitudinally between a forward and a rearward position but which is also removable from the frame. A recess (39) in the side of the frame contains the Kammer trigger mechanism (26, 38) that is accessible through a side opening (40) in the frame. A thin side plate (42) drops over the side opening and is held at its side edges and bottom edge by flanges (50) an the side plate overlapping congruent grooves in the frame and is held in place an top by the slide. After removing the slide in the conventional manner, the side plate can be slide upwardly and removed using a finger cutout (48) in the side plate.

The pistol comprises a frame. A trigger is mounted in the frame and is pivotable between a release position and a firing position and spring urged into the release position. The frame comprises a grip portion with a magazine well in which a magazine is removably inserted. A trigger bar is pivotally attached to the trigger and spring urged upwardly. The trigger bar has an abutment member at its rear end which coacts with a sear member that is movably mounted in the frame. A safety member is mounted on the grip portion and is movable between two positions. At its upper end the safety member has a catch for engaging the trigger bar. A second spring urges the safety member into its first position in which the catch pulls the trigger bar down out of engagement with the sear member. The safety member has an abutment face which is engaged by a part of the magazine when the latter is inserted. The part pushes the safety member into its second position in which the catch is out of engagement with the trigger bar.

A firearm includes a frame, a slide, and modular sear and trigger mechanism housings. The frame has fore and rear receptacles integrally formed therein, e.g., upwardly open compartments accessible from the top of the frame. The modular housings house one or more operational components of the firearm, e.g., trigger and sear components, and are configured for "drop in" insertion into the receptacles. Each housing also includes a set of integral slide rails. For assembly, the operational components are attached to the modular housings, and the housings are dropped into the receptacles and secured to the frame. The slide is operably positioned on the slide rails for reciprocating movement thereon. The frame is provided without integral rails and other features for supporting the operational components. Instead, the rails are provided as part of the modular, drop-in sear and trigger mechanism housings, which also support the operational components.

An extractor mechanism with improved reliability is provided having an extractor arm pivotally mounted within a pocket in a firearm slide. The extractor arm includes a body portion and a hook portion, the body portion being disposed within the pocket and the hook portion extending out of the pocket from an opening proximate to the breech face. The hook portion is biased toward the firearm's firing axis and includes a distal edge sized to engage a cartridge rim. The hook portion preferably has a height greater than the body portion and the portions are preferably connected by a curved portion. Two surfaces preferably meet at the distal edge of the hook portion, with the surface more proximal to the breech face being substantially parallel to the breech face and the surface more distant from the breech face, diverging from the breech face at an acute angle.