The 155mm M1 Howitzer was produced from 1942 as a Medium Artillery field gun (later designated M114) and was used by the American Army during WW2. The gun as seen here had a total weight of almost 9 tons and a maximum firing range of 14km (approx. 9mi). To fire the gun it required a separate-loading bagged charge. In some countries the latest variant of this gun, the M114A1 is still in service.
This gun was photographed in the National Museum of Military History in Diekirch, Luxembourg.