Abstract: A cartridge arrangement having a rocket assisted projectile for firing therefrom by ignition of propellant in the cartridge case and for subsequent ignition of a rocket grain within the projectile, in which the projectile has a sealed tubular chamber cavity encompassing a tubular or ring shaped end burning rocket grain, the rear end of which chamber is formed by a combined nozzle block and rear penetrator support which has nozzle openings sealed by ignitable time delay igniter plugs, and the outer, inner, and forward extremities of which are bounded by a thin-walled projectile case, a cylindrical penetrator, and a forward penetrator support, and which ignitable time delay igniter plugs are externally ignitable by the burning of the propellant to enable subsequent ignition of the adjacent end of the rocket grain.

Abstract: A fin assembly is adapted for rear mounting on a projectile. The assembly s a body with a longitudinal axis and a front adapted for mounting to the projectile. A plurality of angularly spaced fins are pivotally mounted on the body for rotating outwardly from an axial to an extended position. Each of these fins has a pivot point and a center of gravity. The center of gravity for each fin in the axial position is spaced radially inward from the pivot point. Slots formed within the projectile body aid in retaining the fins in their axial position.