Field gun

Originally the term referred to smaller guns that could accompany a field army on the march, that when in combat could be moved about the battlefield in response to changing circumstances (field artillery), as opposed to guns installed in a fort (garrison artillery or coastal artillery), or to siege cannons and mortars which are too large to be moved quickly, and would be used only in a prolonged siege.

Even the German super-heavy guns in World War II were rail or caterpillar-track mobile.

The most common field guns of the era were the British 5.5 in (140 mm), the American 155 mm Long Tom[1] (a development of a French World War I weapon) and the Soviet BS-3 – an artillery piece adapted from a naval gun and designed to double up as an anti-tank weapon.

The M107 was used extensively in the Vietnam War and proved effective in artillery duels with the North Vietnamese forces.

It was considered a high-maintenance item and was removed from service with U.S. forces after a rash of cracked barrels.