Small weapons with such a device can be inferred, for example from Austrian Patents 293 229 and 310 040. The sealing element that locks the cartridge chamber in the back is made of two parts here and includes, on one hand, the butt, which is adjacent to the cartridge chamber on the front, and, on the other hand, a case arranged on the butt that projects over the front, making it generally pot-shaped. The projecting part of the case that includes the propellant charge expands under the pressure of the propellant gas and is pressed onto the inside of the cartridge chamber. Since the resulting gas pressure is quite high, for example 4,000 to 5,000 bar, it has been shown that because of the annular gap between the case and the butt, the seal is not satisfactory, and a loss of pressure occurs that has an effect on the firing. It also means that the base of the pot shape in particular, and if necessary the projecting part of the case, is worn down or damaged.
Austrian Patent 317 726 shows an extractor for cartridges without cases that have a groove around the outside. The butt in this design has an extractor claw that overlaps the propellant charge on one part of the periphery and goes into the peripheral groove. The butt is thus either not coaxial to the running axis or, has a cross section that is not circular, caused by the eccentric extractor claw, so that the design of a bayonet catch is not possible.
The task of the invention is to create a device with an improved, easily produced seal for the cartridge chamber on the side where it locks.