>>There is absolutely no justification for manfacturing this kind of weapon for other than military or police use.

Your issue in the US is that lots of weapons with no obvious civilian application are legally out there. And if ever somebody did manage to increase control, otherwise law-abiding citizens would cache the weapons as a patriotic act in defence of the second amendment. Even if there's a new amendment, the rebels would call themselves the only true patriots and build even bigger caches in defense of the republic. After which the weapons will leak out into the criminal fraternity forever.

I'm not sure what you can do about it now. You might try the Australian tactic involving a time-limited formal buyback program for weapons now declared illegal, but even without the Supreme Court's interpretations favoring individual right to bear arms, that 2nd amendment is a tough one in the US.