Design and testing of a mass-stabilized projectile for a small caliber, electromagnetic launcher

An initial design is presented for a mass-stabilized projectile intended for launch from an electromagnetic railgun. The design utilizes early all the launch package mass for impacting the target and has a reasonable ballistic coefficient for extended range flight. The projectile is comprised of two parts: a tungsten nose tip, and a 7075 aluminum afterbody incorporating a solid armature. The afterbody forms a 'U' and relies on an interference fit to establish an initial preload on the armature/rail interface. A lightweight, discarding bore rider has also been designed to keep the projectile stable during acceleration and represents a small fraction of the total launch package mass. The bore rider prevents armature balloting and supports the nose afterbody interface. Attention is given to design considerations, test results from two electromagnetic launcher firings, and flight characteristics obtained after launch by a conventional gun.<>