Abstract: A canister cartridge projectile utilizes gun gas pressure, bled from the r of a projectile through flow control orifices in a sabot body to a piston contained therein, and set-back acceleration to sequentially eject a payload and a nose cone assembly. The nose cone assembly is attached to the sabot by a plurality of detent lugs which are unlocked on setback by the movement of a slidable ring. Two O-ring seals positioned between the sabot and the nose assembly and the sabot and the cartridge assembly provide moisture protection for the projectile interior and the cartridge propellant charge.