effect brought about by tail 6 which could be made in the pure conical form by replacing the various successive supports 9 fig2 shows an alternative embodiment in which tail 6 has two supports 9 1 and 9 2 designed to cooperate with frustoconical bore 7 a cylindrical bore 12 extends beneath the frustoconical bore as viewed in fig2 and axially inside body 1 to intersect at least one of transverse planes if areas of less resistance 11 exist head 4 is mounted as stated above such as to cause supports 9 1 and 9 2 to rest against frustoconical bore 7 while leaving gap 10 installation of head 4 is however performed after a block 13 made of material which is radially deformable when subjected to radial compression such as rubber has been placed inside bore 12 installation is thus effected such that tail 6 is extended by a cylindrical end part 14 that must be kept in contact with the corresponding transverse face of block 13 cylindrical and part 14 can be composed of an independent part or of an extension of tail 6 extending beyond frustoconical support 9 2 the operation of the projectile on impact is of the same kind as described above due to the presence of gap 10 indeed relative displacement of body 1 relative to head 4 results in forced engagement with a wedging effect of supports 9 1 and 9 2 inside frustoconical bore 7 locally subjecting body 1 to radial stresses moreover the penetration of tail 6 pushes cylindrical end part 14 whose function it is to apply an axial force to block 13 so as to.