First, I'm not American, so it has little effect on me whatever happens, but I was a gun club member in the UK, when it was still legal, before they banned guns.
The ban meant that criminals could still carry guns (you could buy one in many places I knew about) so obviously it was not banned to stop criminals, and the controls I had to pass in the UK before a gun club would allow me to join were stringent, and actually getting a license to keep guns would have been even more difficult.
So those who are gun trained and authorized have little or no likelihood of going on a killing rampage, te other gun owners would spot any possibility, so I guess we were just caught up in the banning frenzy.
But your constitution gave you that right, to carry guns, BECAUSE the writers KNEW that this was the ONLY final defense the citizens would have against a repressive authoritarian government, i.e. those wise men wrote into law an amendment that protected you from them.
The argument is presented that when they wrote it all anyone had was a musket, which took a trained soldier a few seconds to load and make ready to fire, (so) stopping rash actions, however that may stop crimes of passion (though a Colt pistol will work just as well) but does nothing about premeditated murder.
You need guns because you do have a government which is out of control, and behaves far worse than George III did in his time, you need guns because otherwise one day, you will all be at whoever controls the countries mercy, and mercy is a rare event.
You with guns will be massively outgunned and out weapon-ed against your own military, so the eventual outcome may be very bloody, unless the military decide to side with the people, not the elite in power.
2.5 million trained and seasoned veterans, who have little reason to support the administration, may tip the balance if they are well armed, because you only have 500,000 soldiers under arms, but when the proverbial hits the fan, having your own gun, being properly trained and being prepared to use that gun, may keep you alive until the Cavalry come, if they do at all.
So no, I do not think there is any ground to find an agreement, though they could make a start by making it an automatic 10 year sentence for carrying an illegal weapon, and enforcing it.