No point in debating this because there is a zero percent chance that your proposal will happen.
With the current supreme court rulings on the 2nd amendment you are correct. To change this would take an amendment to the constitution or a "Constitutional Convention". Neither option would look good for Gun control groups as the Rs hold the Senate and House and over 30 states have R Governors. If anything it would lead to further gun right measures. At least currently.
Or revolution and starting over I guess.
just a non starter.
But again, are we talking a gun ban (no more selling) or gun confiscation?