We in Colorado could go ahead and do a buyback of AR-15 and similar, and require license, insurance, training, locked independent storage at ranges, etc. for any who want to retain their weapons. Let Colorado lead based on the Australia model. We have veto proof House, Senate, State Governor, AG, SoS, Treasurer's offices.
@FireMonkey
Tough sell though. Really tough. I grew up in a state where hunting is a part of life. My dad was a gunsmith and a custom reloader. Giving up your hunting tools would be like cutting off a limb.