The M10 used in the film is not a machine gun. It's a M10 in 9mm made by RPB Industries. It's an open bolt semi auto pistol. To make it fire in automatic they either changed the trip in the fire control or changed the bolt to a shaved down one to clear the trip. When Isaac Hayes was shooting, the armorer just replaced the modified parts with the original parts for semi auto firing. This is why the ATF stopped the manufacturer of open bolt guns. There's no selector on the left side of the gun. Only the machine pistols had the selector. I have this pistol. Just need to build the fake suppressor and source the scope and mount. Should be fun at the range.