The 105-mm Howitzer Motor Carriage M7 was an American self-propelled artillery vehicle produced during World War II. It was called the Priest by the British Army, due to the pulpit-like machine gun ring. The first M7s produced were modified M3 Lee medium tanks. The M7 went through a fairly rapid shift from being based on the M3, to having more in common with the M4 Sherman. The first major example was an adoption of the M4's three piece housing, single piece casting and suspension. In British service, some M7s carried a radio set, which took the place of twenty-four rounds of ammunition. In U.S. service, the M7 was a resounding success. During the Battle of the Bulge, each U.S. armored division had three battalions of M7s, giving them unmatched mobile artillery support. A total of 3,490 M7s were built and they proved to be reliable, continuing to see service in the U.S. and allied armies well past World War II. Created in 1944, this field manual reveals a great deal about the Priest's design and capabilities. The manual prescribes the duties to be performed in the service of the M7, by firing battery personnel. Originally labeled restricted, this manual was declassified long ago and is here reprinted in book form. Care has been taken to preserve the integrity of the text."