On a small scale, the National Guard confiscated guns in the Katrina aftermath and nothing really happened. Many places have passed some significant gun restrictions and haven’t seen much resistance. I myself think that a national ban would go off without too much resistance, monitoring and maintaining a national gun ban wouldn’t work because of the expense probably, not because of resistance. Good citizens typically comply with laws, even if they disagree.
And there is no disagreeing with that without being moderated.