The decomposition of a projectile in a target body, particularly a hunting projectile in wild animals after penetration therein, determines the energy output of the projectile and thereby the effect of the shot. For projectiles with double cores, the properties of the ingredients used in the cores decisively affect the decomposition and particularly the deformation behavior of the cores. According to the invention, a partial decomposition projectile comprising two cores is provided with one solid core (3) made of a material suited to said projectile and the second core (4) is made of a powder (5) consisting of metal or ceramic ingredients, said powder being pressed to become free of shrink holes, in order to improve decomposition behavior control.