GUN LINE Army Sgt. John Mazza lays in the gun line using an aiming circle to ensure that three 81mm mortar systems are aiming at the same target on Camp Ethan Allen Training Site in Jericho, Vt., Feb. 8, 2014. Mazza, a mortarman, is assigned to Vermont National Guard's Headquarters Company, 3rd Battalion, 172nd Infantry Regiment. The soldiers conducted the live fire-exercise to prepare them for their upcoming rotation on Fort Polk, La. SHARE: Download: Full Size (0.05 MB) Credit: VIRIN: 088324-G-VJP26-790.jpg Photo Gallery