Originally designed and patented by Gordon Ingram in 1948 and later produced in very limited numbers by the Police Ordnance Company. This was one of the newer type submachine guns designed by Gordon Ingram. Later, he gained fame by designing the very successful MAC-10 and MAC 11 SMGs. Although this weapon is similar in outward appearance to the Thompson sub-machine gun, it is very different and uses a machine bolt and barrel assembly with various stamped sheet metal parts including the receiver similar to the MP40 and STEN submachine gun concepts. It fired from an open bolt in a simple blow back manner with a fixed firing pin and a 2-stage trigger. If you pulled the trigger half way back it was a semi-automatic and all the way back it fired in full-automatic. The chamber is marked "INGRAM PATENTS PENDING/ POLICE ORDNANCE COMPANY/ LOS ANGELES CALIF. U.S.A./ M6 MILITARY CAL. .45 A.C.P." It has a standard blade front and simple windage adjustable rear sights. It has a two-piece pistol grip/stock assembly with a horizontal forend. It is complete with one stick magazine and a British canvas sling. As noted, this SMG is registered as a Class III/NFA weapon. It has been deactivated by welding a plug in the chamber of the barrel and then welding the barrel collar to the front of the receiver.