Abstract: A projectile adapted to be given a rotation on being fired which makes the projectile spin-stabilized.With the object of facilitating the terminal guidance of the projectile or increasing the effect of an explosive charge with a hollow-charge effect carried by the projectile, the projectile is provided with stabilizing fins (6-9) which are extended at a desired point in the trajectory of the projectile and brake the rotation of the projectile. The projectile is so dimensioned that its center of pressure (C2) is situated behind the center of gravity (G) of the projectile in the extended position of the fins (FIG. 2) and so that the center of pressure (C1) lies in front of the center of gravity of the projectile in the retracted position of the fins (FIG. 1), so that, with braked rotation, the projectile changes over from being spin-stabilized to being fin-stabilized.