Marines from 3rd Battalion, 10th Marine Regiment, 2nd Marine Division, fire the M777A2 lightweight 155mm Howitzer cannon during a five-day battalion-sized training operation here, Feb. 2 - 6. One of the highlights for the Marines during the training was re-familiarizing themselves with the M777A2 and blasting off live rounds. - Marines from 3rd Battalion, 10th Marine Regiment, 2nd Marine Division, fire the M777A2 lightweight 155mm Howitzer cannon during a five-day battalion-sized training operation here, Feb. 2 - 6. One of the highlights for the Marines during the training was re-familiarizing themselves with the M777A2 and blasting off live rounds.