The subject of the invention is both a method for manufacturing a cartridge case by way of cold forming of seamed or seamless pipes and a cartridge case manufactured by way of subsequent coupling of deformed pipe by the method of the invention with a bottom of the cartridge case by known ways of joining (welding, soldering, forming, pressing, etc.). The invention belongs to class F24B5/02 of the international patent classification.

The technical problem solved by the present constructional solution to the cartridge case and the method for manufacturing thereof is providing serial manufacturing of cartridge cases of various calibres from conventional seamed or seamless pipes. The method of the invention further allows more flexibility in production due to a wider assortment of adequate materials, and last but not least said method is more price efficient and has considerably less production phases compared to the currently known way of manufacturing cartridge cases.

A known way of manufacturing cartridge cases is extrusion of a case by means of big and differently shaped pins, which are used to shape a cartridge from the basic material being in the form of a disc. Successive cold forming of a disc creates the shape of a case having a wall of adequate thickness. The bottom of the case is formed at the end by using a special tool. Problems that appear in the manufacture of this type mostly relate to the conditions of use of an adequate material, which must allow cold forming and be simultaneously tough enough not to break during forming.

The cartridge case is manufactured according to the method of the invention from a conventional seamed or seamless pipe, from which the final shape of a tubular section B is formed with cold forming of the pipe. Then a bottom C of the case, which had been produced by cutting, is joined with the formed pipe section B in various ways like welding, soldering, forming, pressing, etc. in order to manufacture a cartridge case.

The invention will be explained in more detail on the basis of an embodiment and the enclosed drawings, showing in:

Figure 1 schematic presentation of the first phase of pipe forming by the method of the invention;

Figure 2 schematic presentation of pipe forming with a second-stage tool according to the method of the invention;

Figure 3 schematic presentation of manufacturing of a cone section of the pipe according to the method of the invention;

Figure 4 schematic presentation of pipe calibration according to the method of the invention; Figure 5 cartridge case in cross-section manufactured according to the method of the invention before and after placement of the bottom C of the case to the deformed pipe B.

5 The method for manufacturing a body of a cartridge case with the process of cold forming of seamed or seamless pipes is first based on the formation of the specific shape of the pipe B. At one end of the pipe B that has an adequate diameter representing the basic diameter of the case and adequate length representing the length of the case, a passage A from the

10 larger diameter of the pipe B to a smaller diameter is produced by means of a first-stage tool 1 . Then a second-stage tool 2 and a pin 3 are used to produce the final shape of the passage A at one end of the pipe B. A further tool 4 and a pin 5 are used to deform the basic shape of the pipe b into a cone shape, wherein a pin 6 is used to calibrate the opening at the i s passage A of the pipe B. After the pipe B is deformed, both final openings are levelled by means of turning.

To form the cartridge case the so formed pipe B is added the bottom C of the case, which was manufactured by the cutting process and is joined at one end with the formed pipe B by known joining processes, e. g.

20 welding, soldering, forming, pressing, etc.

The cartridge case manufactured according to the method of cold forming of seamed or seamless pipes B and then addition of the bottom C of the cartridge has several advantages over the conventional method of manufacturing cartridge cases by the method of cold forming from the basic disc shape, e.g.:

- simple multi-serial manufacturing of cartridge cases of various calibres from conventional seamed or seamless pipes;

- better manufacturing flexibility due to a wider assortment of materials;

- more price efficient manufacturing method;

- less manufacturing stages;

- allows higher loads in the manufacture.