An M1A1 Abrams tank heads out on a mission. An M1A1 Abrams tank heads out on a mission from Forward Operating Base MacKenzie in Iraq on Oct. 27, 2004. The Abrams and its crew are assigned to Bravo Troop, 1st Battalion, 4th Cavalry Regiment, 1st Infantry Division. SHARE: Download: Full Size (0.08 MB) Credit: VIRIN: 025472-N-PLU11-810.jpg Photo Gallery