The sten was junk ! The Limeys only used it because after the butt whipping they got in France , early on , they lost most of their equipment and needed a cheap and easy SMG . Think of the sten as a Volksturm weapon . It will shoot , but its a pile in every other way . British soldiers got rid of it at every opportunity in favor of either the Tommy or the Grease gun . The side mounted mag was awkward to say the least , and not real practical in street combat . Even the Russians found a way to make a cheap , stamped SMG that turned out to be so good , that even the Germans preferred it over their own , it was the PPSH , and it probably took less to make than the Sten . I shudder to think somebody is going to try it with a 3D printer . Train a Chimp to do the test firing , because I dont think too many humans will be very willing .