and new contracts for tactical and training tank ammunition from the U.S. advanced armor piercing , kinetic energy tank cartridge in the U.S. arsenal. training round used by the Stryker Brigade Mobile Gun System vehicle. training ammunition to the U.S. Army , U.S. Marine Corps , and NATO allies. management is headquartered in ATK 's Plymouth , Minnesota facility. be found on the Internet at http : / / www.atk.com.