Method of sealing the front of a cylindrical sleeve body of a practice cartridge

A method of closing the forward portion or region (u) of a cylindrical sleeve body (3) of a practice cartridge (1), wherein a predetermined number of inside and outside radial folds (8, 7, respectively) are created in the forward region (4) of the sleeve body (3) in two work cycles, and wherein circular arc-shaped inside folds (8) of predetermined depth are created during the first work cycle by the application of radial pressure using correspondingly shaped profiling tools. To achieve secure closing of the sleeve body (3) through folding in a simple and cost-effective manner and without predetermined fracture points resulting in the region of the inside folds (8) during closing, the inside folds (8) are created in the forward region of the projectile body (3) during the first work cycle so that a first, central opening having a diameter of at least 2 mm remains between the inside folds (8) after completion of this work cycle. Due to this first step, tools that have a relatively large bending radius can be used for creating the inside folds, despite the high number of folds. In the subsequent second work cycle, a further radial pressing together of the inside folds (8) is effected by exerting pressure on the outside folds (7), e.g. by using a conical die.