Abstract: A device for protecting the fins of a projectile having a cylindrical houg with a closed base, a side wall and an open end, the closed base having a seat for transmitting a portion of the propellant forces used to launch the projectile to the fins, the open end having pivotably attached a number of petal enclosures in the shape of a frustrum of a right circular cone with a contoured surface at one end. A modified sabot retaining ring keeps the petals in a closed position against the projectile. Either a spring, a petal bell or an explosive is used for opening the petals after the projectile exits the muzzle end of a launcher.