It's only helpful if Fedgov would follow court rulings.
The money quote from US v. RIA
In sum, since enactment of 18 U.S.C. sec. 922(o), the Secretary has refused to accept any tax payments to make or transfer a machinegun made after May 19, 1986, to approve any such making or transfer, or to register any such machinegun. As applied to machineguns made and possessed after May 19, 1986, the registration and other requirements of the National Firearms Act, Chapter 53 of the Internal Revenue Code, no longer serve any revenue purpose, and are impliedly repealed or are unconstitutional. Accordingly, Counts l(a) and (b), 2, and 3 of the superseding indictment are
DISMISSED.
Problem is that ruling only addresses those parts of the NFA supplanted by 922(o). May not have to pay the $200 tax, but now you can't even have something that you otherwise would have been willing to pay the tax on.
So if you have an MG and use this for a defense? What exactly happens? Has anyone tried using it as precendent setting decisions?