If you haven't got access to a gun, then however much you might be inclined to an armed rampage, you're not going to be able to actually do it
I do agree, but I don't see how it's possible to get the US to that place. Access to guns is considered a fundamental right by so many. It will take generations to remove them.
If you can address the reasons why so many are inclined to armed rampage, access to weapons is moot.