Staff Sgt. Daniel Czech, Northern Strike opposing force (OPFOR) member, fires a M240 prior to an ambush during NS 23-1, Jan. 26, 2023, at Camp Grayling, Mich. OPFOR is designed to build readiness for visiting units by introducing injects meant to challenge soldiers in a variety of ways. (U.S. National Guard photo by Staff Sgt. Tristan D. Viglianco)