There's nothing you can do. Nothing. Even if you make the selling of guns completely illegal, how will that change anything? There are still tens of millions of guns in circulation in the USA. Many of them are family heirlooms. The only (impossible) solution now is to buy people's guns off them by having cash-in stations, and that will be only partly affective and painfully expensive. Many will sit tight and refuse to hand them over. What then? You seize people's property? That would shake up the American social fabric so much it just wouldn't work. The political parties would feud over it and if anything you'd see the re-emergence of the Republican party as the governing power in the US for years on end. The guns are a part of America now, and nothing you can do will change that. Perhaps over the course of decades (perhaps more than a century) you can influence things enough to steer people to a place where they don't see the point of guns any more, and just get rid of them, but that's hardly a quick fix. The guns are, heartbreakingly, here to stay. Your best bet is education and proper healthcare for mental illnesses.
>Even if you make the selling of guns completely illegal, how will that change anything? There are still tens of millions of guns in circulation in the USA. Many of them are family heirlooms. It will take a few decades, but the number of guns will go down if they can't be sold, or maintained, or used for practice. This happened in Europe, which was awash with guns after WW2. Another aspect which is often forgotten is ammo. How long does ammo stay good for if stored well?
Europe was awash with guns, but there wasn't a culture that owning a gun was a fundamental right. My grandma took my grandad's gun down to the police station and handed it in. My grandad was a bit upset that it was gone, seeing as though it had been a life-saver etc. for so long, but eventually he stopped his strop. I honestly don't see someone stopping their strop when their SPAS-12 is taken from them because of something someone else did. Mindset is everything.
Your best bet is education and proper healthcare for mental illnesses.
Really, this is what the whole thing boils down to. If someone wants to go kill people they're going to, they may not be able to kill 27 of them, but they'll kill a few. It is about mental health and it is about education. Often it's about inequity, inequality and a feeling of not belonging. I'm not opposed to stricter gun regulation, but getting rid of all the guns in the world won't stop broken human beings from doing broken things.