A projectile for use with a tapered gun bore having a tapered bore section between the breech and the muzzle. The projectile includes an elongated body having a cylindrical bulkhead with a diameter substantially equal to the large caliber section of the gun bore. A tapered ogive extends from the bulkhead to a front end of the projectile while a tapered tail extends from a rear end of the projectile to the cylindrical bulkhead. A plurality of circumferentially spaced forward grooves extend forwardly from the bulkhead and to a point short of the front end while a plurality of circumferentially spaced rearward grooves extend rearwardly from said midsection and to a point short of a rear end of the body.