I'm afraid I have to take the pro-2nd Amendment stance on this one, in no small part because it's been around for all of the USA's existence and yet the mass shooting phenomenon is modern. Something else is the root cause here, and I think the ban guns bandwagon is the result of us collectively not being smart enough about our problems.
The other thing is that, armchair generals about asymmetrical warfare and military defections aside, I will not allow me and mine to be helpless if a political tide sweeps up the right in this country and they decide the time has come for their theocratic dreams to be reality, or there's some other gone to shitness in the future. Live or die, I will not sit around politely and wait to be shot like a fucking dog like people on the internet so like to advocate.
NO POLITICIAN IS GOING TO TAKE YOUR GUNS.
Yes, there are internet morons who want to ban all guns. I myself am more than willing to point out the foolishness of the "protection against tyranny" argument (regardless of its practical concerns, the very idea is apocalyptic fantasy). Nonetheless, it is politically and practically impossible to ban guns on an effective level.
Every time this happens, it just goes in circles. Idiots say "ban guns!" Morons reply, "don't ban guns!" Both of them somehow think they are solving the mass shootings problem. Liberal idiots can't seem to parse that it is literally impossible to achieve that goal. Conservative morons don't seem to realize that somehow the only civil right they've ever championed is the one to keep and hold deadly weapons.
Shut up about the damn guns and provide a concrete, alternative solution. Are Republicans going to allow for a massive mental health reform in the United States? Or does it
cost too much? If we want to have an adequate safety net, that means that pretty much every American is going to, at some point, receive mental care in the same way that every American goes to the doctor once in a while.
EDIT RE. Ninja:
If you're actually prepping for an apocalypse and feel you have nothing to live for on earth, maybe you should talk to some kind of councilor instead of buying guns.