Establish a chain of custody/registration/VIN# type of code for every gun/bullet sold.
Any gun used in a crime will result in all persons in that chain of custody being held criminally and civilly liable.
Suspend 2nd amendment rights of anyone in the chain of custody including private sales, gun shops/stores, gun shows, and gun manufacturers until all investigations into their responsibility involved in that gun being in that criminal or mentally unstable persons hand is completed
Allow victims of crimes committed by guns to sue everyone in the chain of custody of that weapon up to and including the gun manufacturer
Levy taxes on guns and bullets. Chris Rock- if bullets cost $5000 people will be less inclined to fire them due to the expensive nature of discharging that bullet