Abstract: Increment charge for a finned projectile designed to surround a cartridge tube on the projectile and to be ignited by the ignition gases from a propellant and ignition cartridge included in the cartridge tube. The surface of the increment charge which faces the cartridge tube is enlarged in that it is provided with a number of recesses which provide access for the said ignition gases. The increment charge consists appropriately of a number of powder discs of horseshoe-shape, provided with holes, the inner edge of which is asymmetric relative to the aperture of the horeshoe-shape. Each alternate disc is inverted so that the shape of the hole edge is inverted in mirror fashion for each alternate disc.