Designed for The US Navy and Marine Corps, The Rising Model 55, was considered a "cheaoer" version of The Thompson Machine Gun. It used a .45 Cal. Round and could use both a 12 or 20 round Straight Clip. It featured a folding Wire Stock, for firing stability. Weighing 7-pounds, The Model 55s barrel wad 11-inches (with an overall length of 29-inches). Over 100,000 were originally produced. The weapon was considered by Proponents, "ideal" for Jungle Warfare (1942). It wasn't. The M55 suffered horribly from jamming due to dust, dirt, sand and humidity. Although abandoned early, The Model 55 was still used as a Boarding weapon in The US Navy.