The answer to the American Gun Tragedy is twofold:
1. Gun owners maintaining state issued licenses to be in possession of a firearm... with criminal culpability a possible outcome if you put a weapon in the hands of anyone not in possession of a license - even in a private sale to uncle Teddy.
2. Codify on a national level two lists.
One of firearms that the general public can have access to - I'd pay genuine U$ Currency to some American entrepreneur for 3 shots at blowing something up with a bazooka in a controlled and insured environment, but I don't think anyone should be able to keep a bazooka in their closet.
The second of course would be a list of weapons that the general public can collect.
Will there be voices demanding that both lists be very short and boring? Just as sure as there are extremist voices bitching that their second amendment permissions are already being violated because the FBI won't let them have a bazooka in their closet. For democracy in this republic to survive and thrive the moderate voices need to begin to negotiate in earnest and drag the extremists from both sides in to The 21st Century, kicking and screaming like little girls all along the way if necessary.
The majority of Americans will NEVER stand for a denial of access to and ownership of firearms AND the majority of Americans want The American Gun Tragedy to start looking more like history and less like news. Democracy wasn't completely gelded by the Republican victory in The American Civil War... A big enough majority will eventually push even a powerful and entrenched republic.
The answer is twofold.