Projectile for smooth bore weapon

An explosive device, comprising a projectile to be fired from a weapon having a smooth bore barrel and a cartridge case at least partially enclosing said projectile prior to firing, said projectile having:

• a) a warhead having an explosive charge;
• b) a casing having means for joining said casing to said warhead;
• c) a firing pin disposed in said casing, whereby forward motion of said projectile imparts forward acting inertia to said firing pin;
• d) a safety pin for locking said firing pin in a safe position, said safety pin being approximately radially oriented in said casing and slidably engaging said firing pin, whereby deceleration of said projectile caused said inertia of said firing pin to impose a force on said safety pin;
• e) means for exerting a radial force propelling said safety pin radially outward, thereby disengaging said safety pin from said firing pin;
• f) restraining means for restraining said safety pin against said radial force prior to firing said projectile;
• and
• g) a plurality of fins affixed to said casing and having means for assuming radially retracted and radially extended positions for restraining said safety pin against said radial force for a predetermined period of time after said projectile leaves a weapon barrel, said fins having means for causing sufficient deceleration of said projectile when assuming said extended positions so that said force imposed by said firing pin on said safety pin is sufficiently great to restrain said safety pin against said radial force for said predetermined period of time.

An explosive device comprising:

• a) a cartridge case including a propellant charge, and
• b) a shotgun projectile for use in a shotgun having a barrel and a chamber, said projectile having a generally cylindrical casing and warhead assembly, said warhead being hollow to accommodate an explosive charge and an initiator, said casing having:
• (i) a firing pin spring biased to a safety position, (ii) a safety pin extending approximately radially through said casing and engaging said firing pin, thereby locking said firing pin in said safety position, (iii) means for biasing said safety pin radially outward, and (iv) a plurality of fins pivoted to the periphery of said casing so as to be capable of assuming both a folded-down upon said casing position and a radially outwardly deployed position, wherein said projectile is at least in part retained prior to firing in said cartridge case, whereby said cartridge case retains said fins in said folded-down condition, whereby said safety pin radially disengages from said firing pin under the urging of said biasing means and said fins deploy radially outwardly subsequent to said projectile exiting from a shotgun barrel, whereby said deployment of said fins causes deceleration of said projectile sufficient to cause said firing pin to impose a shear force on said safety pin that delays said disengagement of said safety pin from said firing pin for a predetermined period of time after said projectile leaves said barrel.