U.S. Army paratrooper Staff Sgt. Duwayne Johnson, assigned to 1st Squadron, 91st Cavalry Regiment, 173rd Airborne Brigade, reviews his shot group during M4 carbine zeroing at the Infantry Training Area in Hammelburg, Germany, Jan. 28, 2015. Paratroopers from the brigade combined with allied troops from the German Armed Forces United Nations Training Centre for a two-day training exercise. (U.S. Army photo by Visual Information Specialist Markus Rauchenberger/released)