surface to sheer off during projectile penetration into a sheet of armor is enhanced the outer skin of the projectile can act as a lubricant to reduce friction between the projectile and the armored sheet so that the projectile has greater ability to penetrate the sheet also the fibers may parallel arrow 46 which in turn parallels line 48 showing placement of a ridge on projectile 10 the ridge is formed by one of grooves 28a d as the projectile is fired for purposes of illustration an exaggeratedly radially thick ridge is shown at 50 in fig9 and 10 orientation of the fibers parallel to arrow 46 maximizes the degree to which jacket 12 can be radially compressed and still retain memory of its original shape thus when projectile 10 leaves barrel 26 jacket 12 will tend to return to return to its original shape and the ridges 50 will reduce in size or disappear the reduced ridges are illustrated at 52 in fig9 and 10 the smaller or absent ridges will reduce aerodynamic friction as the projectile spins during its flight toward a target as a further option it may be desirable for some applications that the fibers not extend rearward beyond dumbbell 20 absence of fibers rearward of dumbbell 20 will enhance.