The Miller case is okay. What's a crock is the way it has been applied, again, for the OPPOSITE of what it stands for. Courts get away with this, because not many people read the precedents and find out the courts rationale is bogus. That is, the courts lie about the law.
The SCOTUS remanded the case to the court below, with (coded in legalese) instructions to obtain evidence. If the evidence showed a sawed off shotgun had a militia use, or was useful for the common defense, then the dismissal of the charge was to be reinstated, and the 1934 NFA (tax on firearms) was to again be held an unconstitutional infringement of the RKBA.
It has since been watered down further by the "common use" idiocy of Scalia who is supposed to be "conservative". There is no logic to the arguement that "Machine guns aren't in common use, so it's ok to keep them banned even though they are only banned by unconstitutional means".