Abstract: The device for firing a diabolo form bullet from a firearm with a rifled barrel consists of a cartridge having a housing, a detonation cap connected to one end of the housing in a gas-tight manner and containing a gas-forming propellant, the housing having an expansion compartment for expansion of a gas produced on ignition of the gas-forming propellant and an outer surface tapered toward another end of the housing remote from the detonation cap, the tapered outer surface aligning the diabolo form bullet loaded coaxially in the rifled barrel by engaging a tapered recess provided in the diabolo form bullet, whereby the diabolo form bullet is forced into the rifled barrel so as to calibrate the diabolo form bullet; and a membrane covering the other end of the housing remote from the detonation cap. The housing is provided with at least one breakthrough region, which ruptures when a gas pressure on ignition exceeds a predetermined maximum value.

Abstract: In a cartridge fitted with a gun-barrel projectile comprising a lead head and a resilient body joined to the head by a plug-in connection, the connection is designed to be a positive and exact fit, and the body is constructed with a forward end part adjacent the head, a rod-like central part, and a rearward end part in the form of a flat top piston connected to the central part at a predetermined breakage point whereby the rearward part can break from the central part and move forwards, hence moving the center of gravity of the projectile forwards, when the cartridge is fired.

Abstract: A cartridge includes a gun barrel bullet made up of a metal head and an elastically deformable plug made up of two parts. The first plug part is connected to the head and defines an open ended chamber which is closed off by the second plug part. The first part includes a tapering pin which projects downwardly through the chamber and engages in an opening in the second part so that on firing the bullet remains an integral unit.