In a new twist to the ongoing story of the US Army’s XM25 CTDE “Punisher” airburst infantry grenade launcher, Orbital ATK, a technology partner on the program, has sued fellow partner Heckler & Koch for failure to deliver 20 units of the new weapon. Orbital ATK is seeking more than $27 million in damages from H&K, and transfer of some intellectual property to another contractor. Orbital ATK says that Heckler & Koch’s failure to deliver the weapons has jeopardized its contract with the US government, raising the chance of program termination, and at least causing a substantial delay.

Heckler & Koch denied the claims and refused to make a statement. However in a filing with the U.S. District Court in Minnesota, it was noted that H&K apparently sought a confirmation over whether airburst infantry weapons would be legal for warfare under international law. According to Reuters, the company even requested the US government provide a special certification for the weapons.

Orbital ATK was formed via a 2015 merger between Orbital Sciences and Alliant Techsystems (ATK), creating the 33rd largest defense contractor in the world. ATK has been partnered with Heckler & Koch on the program since it was the XM29 OICW combined kinetic-explosive weapon. The former company was responsible for the munitions, optics, and fire control, while the latter was responsible for the architecture and housing.