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Some collectors hunt for firearms which look perfectly new form the factory, and others prefer arms that show lots of evidence of use and history. Well, this is definitely one of the latter type - this 1943 production MP40 submachine gun has a terrible finish, most likely as a result of being buried for a period of time. It also has a crudely fabricated and attached brass-catching bag. The muzzle nut is missing as well - possible just lost, or possible removed to attach a suppressor along with the brass catcher.
There is no way to know for sure, but the evidence all taken together suggests that this is a weapon captured and modified by Soviet or Ukrainian partisans during the latter years of World War Two.
Thanks to the Association of Maltese Arms Collectors and Shooters (http://www.amacs-malta.org) for providing this unique submachine gun for video!