Tracer Round
Gunnery Sgt. Dragos Coca engages targets during a desert survival and tactics course. Coca is a platoon sergeant with 15th Marine Expeditionary Unit. Elements of the 15th MEU trained with the 5th Overseas Combined Arms Regiment in Djibouti from Sept. 21 to Oct. 7 in order to improve interoperability between the MEU and the French military.
(U.S. Marine Corps photo by Sgt. Steve H. Lopez/Released). Original public domain image from Flickr