M781 chalk rounds are fired from a Mark 19 40 mm grenade

M781 chalk rounds are fired from a Mark 19 40 mm grenade machine gun during Task Force Ultimate, Operation Cold Steel II, hosted by U.S. Army Civil Affairs and Psychological Operation Command (Airborne) at Joint Base McGuire-Dix-Lakehurst, N.J., July 28, 2018. Operation Cold Steel is the U.S. Army Reserve’s crew-served weapons qualification and validation exercise to ensure that America’s Army Reserve units and Soldiers are trained and ready to deploy on short notice and bring combat-ready and lethal firepower in support of the Army and our joint partners anywhere in the world. (U.S. Army Reserve photo by Staff Sgt. Christopher J. Sofia/78th Training Division)