Abstract: The invention provides a projectile adapted to be fired from a smooth bore weapon, such as a shotgun, by means of a cartridge containing a propellant charge. The projectile comprises a generally cylindrical casing and a warhead assembly, the warhead being hollow to accommodate an explosive charge and an initiator, the casing being formed with a firing pin spring biased to a safety position and locked in the safety position by a spring biased safety pin. The spring biased safety pin is adapted to release the firing pin in a predetermined period of time after the projectile exits from the weapon. The casing includes a plurality of fins foldable within the cartridge, but which deploy radially on leaving the weapon.