BARREL BUDDIES U.S. Marine Gunnery Sgt. Jason Neale, right, and U.S. Navy Petty Officer 3rd Class Zach Cirocco demonstrate how to change the barrel of an M-240B machine gun during weapons training at the Sierra del Retin weapons range in Barbate, Spain, April 19, 2011. Neale is the military advisor for Naval Mobile Construction Battalion 74 and Cirocco is a construction mechanic. SHARE: Download: Full Size (0.09 MB) Credit: VIRIN: 515745-B-BRS55-307.jpg Photo Gallery