A method of firing a firearm includes compressing a main spring to rotate a latch pin lever; forcing a latch pin forward by the latch pin lever to force a cylinder forward toward a barrel; sealing or substantially sealing the barrel and the cylinder; and releasing a hammer to strike a cartridge while the barrel and the cylinder are sealed.

A containment facility for a revolver has first and second opposed cups which embrace and seal against the opposed side faces of a revolver frame. The revolver cylinder resides within an aperture defined by the frame, and the cups enclose the exposed portions of the cylinder. The first cup defines a first internal space and has a first rim configured to conform with the first side face contour of the revolver frame, and encompasses the cylinder aperture with a first portion of the cylinder received in the first internal space. A second cup defines a second internal space and has a second rim similarly configured to conform with the second side face contour of the revolver frame, and encompasses the cylinder aperture with a second portion of the cylinder received in the second internal space. The containment facility includes flexible gaskets between the cup rims and the frame side faces.

A method of firing a firearm includes rotating a trigger to force a latch pin lever to move; forcing a latch pin forward by the latch pin lever to force a cylinder forward toward a barrel; sealing or substantially sealing the barrel and the cylinder; and releasing a hammer to strike a cartridge while the barrel and the cylinder are sealed.

A speed-loading device for loading the multi-chamber firearm, such as a revolver, by placing the axial centerlines of the cartridges over the centerlines of the chambers in the revolver's cylinder, pulling the fingertab away; thus, rapturing the tear-off portion of the first bracket and releasing the first cartridge into the firearm. By continuously pulling the tab, the sidewalls of the second and then all remaining brackets are getting pulled further apart, their openings widen and the cartridges slide off their brackets and free-fall into their respective chambers.

A specialized underwater pistol with ammunition includes one or more of barrel expansions to shape the pattern of the plural shot pieces expelled from a pistol cartridge when the pistol is fired, an aerodynamic trigger cam or spur, flushing ports, a wide trigger pull, a wide hammer spur, a cartridge shot carrier with a frangible end, and cartridge sealant.

A specialized underwater pistol with ammunition includes one or more of barrel expansions to shape the pattern of the plural shot pieces expelled from a pistol cartridge when the pistol is fired, an aerodynamic trigger cam or spur, flushing ports, a wide trigger pull, a wide hammer spur, a cartridge shot carrier with a frangible end, and cartridge sealant.

A cylinder impeller for revolvers, which transmits the trigger pulling movement to a cylinder revolving movement. The impeller includes a cover having inside it a track; a one-piece body having a plate and a slider, said slider being able to slide within and relative to the cover; and a spring arranged between the body slider and the surface of the cover track. Therefore, the cover and the body slide one relative to the other and against the spring action, thus varying the overall length of the impeller and compensating and absorbing possible teeth machining variations of the cylinder extractor.

A cylinder impeller for revolvers, which transmits the trigger pulling movement to a cylinder revolving movement. The impeller includes a cover having inside it a track; a one-piece body having a plate and a slider, said slider being able to slide within and relative to the cover; and a spring arranged between the body slider and the surface of the cover track. Therefore, the cover and the body slide one relative to the other and against the spring action, thus varying the overall length of the impeller and compensating and absorbing possible teeth machining variations of the cylinder extractor.

A firing mechanism for a firearm includes a trigger, a forcing structure, and a spring within a cylinder, wherein while the trigger is pulled, the forcing structure moves to force the cylinder to contact a barrel and to force the spring to compress, and while the trigger is returned to an idle position, the forcing structure moves to allow the spring to decompress and to force the cylinder away from the barrel.

A firearm lock mechanism includes a trigger, a hammer, a stirrup connected to the hammer at a stirrup connection point, and a spring operably connected to the stirrup at a spring connection point. Progressive pivoting of the trigger drives corresponding progressive pivoting of the hammer. The stirrup connection point is disposed forward of the hammer pivot point. One of the spring connection point, hammer pivot point, and stirrup connection point is offset relative to and laterally spaced between the others of the points to be a vertex of an intermediate angle cooperatively defined by the points. The angle increases in magnitude as the trigger drives pivoting of the hammer. A toggle line is defined between the trigger pivot point and the hammer pivot point. The trigger contacts the hammer at a contact point that shifts across the toggle line as the trigger drives pivoting of the hammer.