Ultimately, guns are not very complicated machines. I'm making a semi-automatic rifle in my home office right now out of stuff you can get at a hardware store & some 3D printed parts, and I'm amazed at how simple it all is.
A lot of proposed gun control feels like trying to put the genie back in the bottle. Even states with hefty assault weapon bans like California and Maryland still have plenty of legal loopholes allowing people to own semi-automatic guns, and gun manufacturers are finding more all the time. I honestly think that anything short of straight up banning the sale of gunpowder will have a temporary at best effect on gun violence, and do less than nothing at worst.
The fact of the matter is that gun control bills at the federal level will cost a lot of political capital. A federal challenge to the 2nd amendment will rally conservatives in the same way that the recent overturning of Roe caused a surge for liberals. This is to say nothing about enforcement: it's a common position among gun owners that they would simply refuse to comply with a gun confiscation / surrender, and I believe a significant chunk of them would follow through with that. See the recent ATF rules about pistol braces for an example of mass non-compliance.
So, we can fight the uphill battle of gun control for perhaps marginal returns, or we can try to address the things that drive people to violence in the first place. And I'm not just saying "muh mental health" either; we need to address housing costs, healthcare costs, education costs, wages stagnating behind inflation, broken-windows policing, the war on drugs, the mainstreaming of far-right propoganda, the decay of public schooling, white supremacy, queerphobia, misogyny, climate change & doomerism, corporate personhood, and a fuckload of other things making people angry and desparate and hopeless enough to kill people & themselves.
I firmly believe that addressing the material conditions that create killers will prevent more murders than any gun control bill, especially in the USA.