Abstract: A system for controlling muzzle torsional movement about the axis of a rifled gun tube during firing by applying to the muzzle a counter-torque symmetrical about the gun tube axis and derived from recoil energy through cam-relation of the gun cradle with a torque tube connecting the gun cradle and muzzle; preferably the cam relation includes a plurality of aperture symmetrically located about the gun tube axis in the breech and of the torque tube, engaging a respective plurality of cam followers on the gun cradle.

Abstract: A semi-automatic firearm having a slide axially movable with respect to a frame between a forward battery position where the firearm is discharged, and a full recoil position where the spent cartridge is extracted and a new cartridge is subsequently loading. Either a pair of oppositely wound, concentric springs or a flat helical spring extends between the slide and the frame to form a recoil mechanism which resiliently biases the slide toward battery. The slide partially surrounds a barrel which is pivotally secured to the frame toward its rear end through a link. The slide contacts the barrel at a point diametrically spaced from the link when the slide is in battery thereby resiliently biasing the barrel in a forward direction which imparts a rotational moment to the barrel about the pivot axis of the link. The rotational moment forces the front end of the barrel downwardly against two distinct support areas on the slide.

Abstract: An automatic pistol of the breech block type which is interconvertible to fire sub-caliber cartridges. The frame, handle, slide, ejector and firing mechanism of the larger caliber pistol are used when converting for sub-caliber usage. A sub-caliber barrel is mounted in the slide and detachably connected to the frame by a pivotal link. An interchangeable barrel bushing adapted to support the forward end of the sub-caliber barrel is inserted in the slide. At the forward end of the slide a recoil spring is tensioned to operate the slide upon firing of a sub-caliber cartridge. A sub-caliber magazine is inserted in the handle. The extractor is cambered and is sufficiently flexible to capture and extract cartridges of both calibers. The cartridge locating recess in the breech face is that of the larger caliber.

Abstract: The accuracy of a semi-automatic piston of the locked breech type is improved by tapering each side of the tenon at the rear of the barrel and correspondingly tapering the tenon engaging recess in the slide, thereby assuring that the rear of the barrel is accurately centered at the breech face of the slide and is prevented from moving laterally. The mating surface of the under-barrel lug is contoured such that when the barrel is in battery the slide stop pin bears against the under-barrel lug in such a manner as to cause the barrel to be jam fitted between the slide stop pin and the underside, top surface of the slide thereby preventing any vertical movement.

Abstract: A return-spring assembly for slide-type automatic pistols in which an inner spring and an outer spring are coupled together so that they work in tandem.

Abstract: A spring steel snap ring bearing between the gun barrel and the barrel bushing to remove the relative play therebetween and thus accurately position the barrel relative to the sights on the slide to improve its aiming characteristics. This relative play between the barrel and barrel bushing on the slide is incorporated in its manufacture to permit pivotal as well as longitudinal movement of the barrel relative to the slide containing the bushing.

Abstract: A semi-automatic firearm having a slide axially movable with respect to a frame between a forward battery position where the firearm is discharged, and a full recoil position where the spent cartridge is extracted and a new cartridge is subsequently loading. Either a pair of oppositely wound, concentric springs or a flat helical spring extends between the slide and the frame to form a recoil mechanism which resiliently biases the slide toward battery. The slide partially surrounds a barrel which is pivotally secured to the frame toward its rear end through a link. The slide contacts the barrel at a point diametrically spaced from the link when the slide is in battery thereby resiliently biasing the barrel in a forward direction which imparts a rotational moment to the barrel about the pivot axis of the link. The rotational moment forces the front end of the barrel downwardly against two distinct support areas on the slide.

Abstract: The apparatus of this invention relates to certain improvements in a handgun which is generally known as "Colt Government Model Automatic Pistol, Caliber .45.

Abstract: A semi-automatic firearm of a type having a barrel loosely coupled with respect to a frame unit, such as the receiver of a pistol, and having a slide member disposed about the barrel and coupled to the frame or receiver unit for movement between advanced and retracted positions relative to the barrel includes accurizing means which serves to remove lost motion between the barrel and the slide where the slide carries the sights of the firearm. Lost motion is removed at the muzzle, at the breech, and in the sliding land-and-groove coupling between the slide and receiver so as to achieve repeatable, accurate performance of the firearm.