Abstract: A folding knife has a handle with a body forming a pocket into which its blade is normally retracted, the pocket being bounded by two cheeks of the holder body traversed by respective contacts in line with a hole near an end of the blade. One cutout is occupied by a plunger which is rigidly connected with a detent, occupying the other cutout by a stem that is integral with either the plunger or the detent and traverses the hole of the blade to serve as its pivotal axle. A spring in the first cutout biases the interconnected plunger and detent into a locking position in which a projection on the detent engages in a notch of the blade to hold it in its retracted or its extended position; the biasing spring may bear directly on a confronting blade surface and coact with one of its notches to prevent a rapid switch into the extended position.

Abstract: To reduce the caliber of a muzzle-loading handgun, an inner barrel is inserted into the normal, outer barrel to which it is positively fastened only at the muzzle end. The rear end of the inner barrel adjoins a nipple, screwed into the breech portion of the outer barrel, which has a rearwardly projecting boss adapted to carry a percussion cap lodged in a recess of a hammer when the latter is uncocked. The nipple has a bore offset from or inclined to the barrel axis to reduce the reaction of the explosive charge upon the hammer when the percussion cap is detonated. The inner barrel fits tightly into the outer barrel in the vicinity of the nipple but is of reduced diameter over the greater part of its length for easier insertion.

Abstract: A revolver-type pistol has a cylinder formed of a front section rotatably mounted on the pistol frame and a removable rear section formed with a plurality of throughgoing chambers each adapted to receive a respective cartridge. This rear section can be removed from the front section with the spent cartridges and replaced by another section so as to allow quick reloading of the pistol. A coupling is provided between the two sections to rotationally link them together and a spring-loaded mechanism is provided to hold the rear section tightly against the front section. The chambers in the rear section may terminate at the front face of the rear section in small holes alignable with similar holes in the front section so that the blank cartridges exploded in the rear section will discharge through these holes. The front section may have a rearwardly extending stem formed with teeth operated by the mechanism of the pistol to rotate the cylinder.