Abstract: The projectile includes a preferably cylindrical body, with an outer preferably generally cylindrical shell disposed over a portion thereof, having a fixed end secured to the body and a rotatable opposite end. The shell bears a number of spaced fins simultaneously moveable between a closed low-profile position and a deployed flight-stabilizing position by rotating the rotatable shell end. Each fin has a pair of elongated plates hinged together at one end, and the fin plates are also hinged to the shell at opposite ends thereof. The plates are aligned in a direction diagonal to the longitudinal axis of the body, while the hinges are also diagonal to that axis so that a rolling moment around the longitudinal axis of the projectile is imparted by the fins during projectile flight. The projectile includes an impeller connected to the rotatable end of the shell for rotation thereof around the body's longitudinal axis.

Abstract: The projectile includes a preferably cylindrical body, with an outer preferably generally cylindrical shell disposed over a portion thereof, having a fixed end secured to the body and a rotatable opposite end. The shell bears a number of spaced fins simultaneously moveable between a closed low-profile position and a deployed flight-stabilizing position by rotating the rotatable shell end. Each fin has a pair of elongated plates hinged together at one end, and the fin plates are also hinged to the shell at opposite ends thereof. The plates are aligned in a direction diagonal to the longitudinal axis of the body, while the hinges are parallel to that axis. The projectile includes an impeller connected to the rotatable end of the shell for rotation thereof around the body's longitudinal axis.