Field artillerymen with 3rd Battalion, 14th Marine Regiment, 4th Marine Division, prepare powder for an M777A2 Lightweight Howitzer before the next call for fire mission at Fort Indiantown Gap, Pa., during exercise Twisted Sister, a battalion fire exercise, Oct. 25, 2014. Before the batteries can fire, the guns receive coordinates from forward observers down range who are the eyes and ears of the gun batteries. (Marine Corps Photo by Cpl. J. Gage Karwick/Released)