It’d be great if guns didn’t exist, but since this would require totally abolishing the current political, legal, and cultural system of the US and replacing it with something new, it’s hard to see how to get there in practice.
To be clear: concretely, you’re advocating total revolutionary overthrow of the present US regime (which is almost guaranteed to lead to civil war) in order to solve the problem of school shootings? Or did I misunderstand you?