The breech of a M777 A2 Lightweight Howitzer after a five-shot volley during an artillery demonstration by Marines with Artillery Instructor Battery, Combat Instructor Company, Instuctor Battalion, The Basic School on Nov. 28. The M777 A2 can fire rounds weighing about 100 pounds onto targets more than 18 miles away. - The breech of a M777 A2 Lightweight Howitzer after a five-shot volley during an artillery demonstration by Marines with Artillery Instructor Battery, Combat Instructor Company, Instuctor Battalion, The Basic School on Nov. 28. The M777 A2 can fire rounds weighing about 100 pounds onto targets more than 18 miles away.