Staff Sgt. Samuel Williams, left, a native of Roseboro,

Staff Sgt. Samuel Williams, left, a native of Roseboro, N.C., and Staff Sgt. Matthew Straub, a native of Sterling, Ill., both assigned to Company B, 2nd Battalion, 8th Infantry Regiment, 2nd Armored Brigade Combat Team, 4th Infantry Division, go through the functions check of an M4 carbine during Expert Infantry Badge training, May 14, 2014. A functions check is required to make sure a weapon will function properly after it is disassembled and assembled. (U.S. Army photo by Staff Sgt. Andrew Porch, 2nd ABCT PAO, 4th Inf. Div.)