Easy “gun control” solution, and the US government would make money off of it (that’s they only way they’ll get involved), and no one would be coming for your guns (bear all the arms you want, it’ll just cost to use them): add a use tax to every shell casing sold, filled or empty. A LARGE tax. Say, $100 a casing.
People would think twice before wasting money en mass. And they’d start recycling all that brass they leave all over the damn place. Sure, a black market would develop, but that’s going to happen with whatever happens anyway.