Army Reserve Staff Sgt. Francisco Contreras, a chemical, biological, radiological and nuclear (CBRN) noncommissioned officer and native of Chicago, Illinois calls troop engagement commands to Army Reserve Soldiers conducting platform gunnery training on a blank firing range on Fort Riley, Kansas, April 4, as part of Operation Gauntlet. More than 450 Army Reserve Soldiers from around the country are participating in the three-week gunnery exercise to hone crucial gunnery skills and increase battlefield lethality. (Official U.S. Army Reserve photo by Sgt. 1st Class Brent C. Powell)