General Dynamics had earlier reported receipt of a similar order for training ammunition as well as for high-explosive ammunition.
ATK said the 120mm rounds, used by M1A1/A2 Abrams main battle tanks, include M865 kinetic energy and the M1002 multi-purpose anti-tank training rounds, which replicate tactical ammunition in appearance and ballistic performance.
"High-quality training ammunition is essential to helping our warfighters prepare for mission success," said Bruce DeWitt, vice president and general manager for ATK's Armament Systems division.
"We leverage our production expertise in tactical 120mm tank ammunition to deliver training rounds that meet performance, reliability, and safety requirements for use on U.S. and European ranges."
The award is for one base year of performance, with four one-year options.
The rounds will be produced at the Allegany Ballistics Laboratory facility, which is a U.S. Navy-owned, ATK-operated facility in West Virginia.