If you limit guns to only being able to fire a few times, it solves pretty much all the problems, while still allowing people to defend themselves.
At that point, why not just limit it to one bullet, because "nobody needs more"?
The amount of ammunition isn't the problem. The firearm isn't the problem.
The problem, is who is holding the firearm, as well as restricting those who are law abiding from carrying because of policies made by those who have armed guards.
You should also limit WHO has them at all, make it like getting a drivers license (at least), but there is really no reason to have a gun that fires more then say 6 shots.
1 shot? Yeah, you can miss, or there could be 3 intruders etc. I'd say a 6 shot gun would work for almost every defensive action. Even if you are being robbed by 3-4 guys, you can shoot all of them, or at least scare them away.
No need for more then 6 shots in 99.99% of cases where you are using a gun defensively.
So step the heck up, and start replacing any guns in the US with ones that can only shoot so many times, and make it illegal to have any other kinds of guns (other then rifles etc that shoot just once for hunting etc).
A specific list of legal guns, and the ability to trade in old guns (that are no longer legal) for a new legal gun.
Still won't be popular, but, I think it could happen without a civil war.
Why 6 though?
Why not 5?
Or 1?
Or 0?
What is the magical reasoning why 6 is the magic number? Are 7 bullets going to make law-abiding citizens more dangerous?