Saboted projectile

A projectile for a conventional ammunition cartridge for firing from a gun having a barrel with a rifled interior surface, said projectile comprising:

• an axially symmetric penetrator having a forward end defining a streamlined wind screen and an aft portion defining a circular cylinder of uniform diameter except for a ring groove defined ban exterior surface of the penetrator near but not at the aft end of the penetrator around which an expandable ring is coupled to prevent the penetrator prior to ring expansion from moving either aft or forward in relation to an armored generally axially symmetrical three piece non-disintegrating sabot comprising as the first piece an axially symmetrical forward section defining an interior circular cylindrical surface slightly greater in diameter than the exterior surface of the circular cylinder of the aft portion of the penetrator, the exterior surface of the forward section increasing in diameter as a function of distance from the forward end of the forward section to a strong bourrelet which prevents wearing away of sabot material which wearing away would cause balloting in the barrel, the exterior surface of the first piece defining at least one portion of greater diameter which mates with grooves of a gun barrel to prevent loss of a substantial amount of gas around the sabot during firing, the portion of greater diameter being fabricated from a material softer than the gun barrel rifling so that said soft portion of greater diameter can be engraved by the grooves of the gun barrel without damaging the rifling grooves, the aft portion of the first piece of the sabot having an exterior surface with at least one indentation capable of removably mating with the forward portion of the casing of a conventional ammunition cartridge, the forward interior surface of the axially symmetrical first piece of the sabot adjacent that portion of the penetrator forward of the penetrator ring groove defining an interior circular cylinder of diameter slightly greater than the diameter of the penetrator, the second piece of the sabot comprising the expandable ring of exterior diameter when not expanded slightly greater than the diameter of the penetrator, and an interior diameter when expanded slightly greater than the exterior diameter of the penetrator and the third piece of the sabot is an armored threaded end cap attached to a rear portion of the first piece by a threaded connection, said end cap having a forward part and an aft part and an interior surface defining an axially symmetrical cylindrical cavity, the cavity opening via an axially symmetrical hole having a smaller diameter than the cylindrical cavity to a rear surface of the end cap and the forward part having an exterior surface defining left threading thereon which is coupled to the aft end of the first piece which has an interior surface defining left handed threading mating with the threading of the end cap to hold the sabot and penetrator together prior to firing, the aft end of the first piece having an interior surface approximately equal to but slightly greater than the exterior surface of the expanded ring in diameter and coupled to the end cap, the cylindrical cavity in the end cap is in contact with the rear end of the projectile, the sabot having a geometry and mass distribution such that its actual gyroscopic stability factor is equal to or greater than that required for achieving stable flight along a substantially predictable and repeatable trajectory, the ring expanding and permitting the penetrator to separate from the sabot during rotation in a rifled barrel during firing so that the penetrator separates from the sabot after leaving the barrel when the force of acceleration on the sabot from firing diminishes sufficiently to permit the non-disintegrating sabot to decelerate backwards from the relative position of the penetrator, wherein the sabot does not disintegrate near the gun muzzle.