I was thinking of doing a semi auto sten rifle build. A mark 5. The only accuracy testing I could find was with a mark 2 sub gun length barrel and was being fired open bolt. The mark 2 has bad eargo, sights are only on the tube reciever. It could hit a person sized target at 100 yards, call it 1 MAN accuracy. No surprise. The ATF approved sten gun rifle fires closed bolt and will have to have a 16 inch barrel to remain a title 1 gun. The sight attaches to the front of the barrel so I'm thinking it could hit 1/2 MAN at 100 yards or a midget. Anyone ever build one?