Electromagnetic gun bore rider

Abstract

An electromagnetic gun assembly includes a gun barrel, a projectile structure disposed within the gun barrel, and a plurality of bore rider members disposed between the projectile structure and the gun barrel. The bore rider members are dimensioned and arranged to maintain the projectile structure spaced-apart from the gun barrel, restrict lateral movement of the projectile structure relative to the gun barrel, accommodate ablative mass loss, and accommodate static and dynamic gun barrel expansion. Each bore rider member has a tapered shape that includes converging first and second surfaces, the first surface facing the gun barrel, the second surface facing the projectile structure, and the first and second surfaces converging in a direction opposite to a direction of acceleration in which the projectile structure is to be accelerated along the gun barrel. Each bore rider member is moveably disposed in a position such that as ablative mass loss occurs to the bore rider member, it moves relative to the projectile structure in the direction in which the first and second surfaces converge to remain wedged between the projectile structure and the gun barrel.