I'm of a different opinion on this now. I'm quite sure that gun ownership is an artefact of a curious cultural situation in the USA which perceives all kinds of threats that no other nation in the anglosphere can perceive. It's this greater threat perception that provides and demands the requirement for individual force, and it's that cultural curio that needs to be addressed before anyone removes any guns from the system.
The other solution is to totally embrace the idea that individuals can only be made safe by multilateral application of force, and so everyone should be trained in the use of, and encouraged to own and actively carry and conceal, firearms. At the moment you've got a sort of half-and-half situation, and so you end up with power discrepancies that result in mass shootings.
I'm down for required Federal Service.
2 years, post High School.
Then you're allowed to vote, run for office, and, carry that shiny new nickel plated 1911.