1. Owning/possessing/drinking/selling alcohol is not enshrined in the Bill of Rights. Congress itself did not ban alcohol, another error - Congress might have written that amendment but it took a two-thirds majority of state legislatures to ratify it.
2. A Constitutional amendment banning something that was in common existence is a far cry from an administrative agency's rule-making. You cannot conflate a Constitutional amendment with an agency's rule on a subject.
Heaven help us if we ever have a Constitutional convention where everything is on the table.
But there have been thousands of proposed amendments and only 27 have been adopted and, if we think about the BofR as literally a part of the original 1787 Constitution, then in 235 years there have only been 17 amendments and the 18th Amendment/Prohibition was repealed by the 21st Amendment because it was so overwhelmingly unpopular, never mind stupid on its face.
Jus' sayin'.....let's not confuse these issues.........
That's what I was getting at. What if, at some point, the constitution is amended to prohibit something that is in common use? It did happen with alcohol, so I would not say that it is impossible with anything firearms related.