- Assault rifle ban. Edit: with a mandatory buyback for newly banned weapons.
- Voluntary gun buybacks with no questions asked to incentive reduction of firearms in circulation
- Football numbers given out to those who are found in possession of a banned or unregistered firearm. Double if it's also found to have been used in the commission of a crime.
- Significant punishment for guns owners whose weapons are used in the commission of a crime without having first been reported as stolen.
- A licensing system similar to a drivers license that must be completed prior to purchasing firearms legally. Ie. Safety courses, a learners permit with X amount of hours that must be completed, and varying classes of licenses that permit you to own and/or operate different classes of firearms.
- As a part of your licensing you must also show proof of purchase of a proper gun storage safe with verifable space inside at the time of any new purchase.
- Also as part of licensing is the creation of a gun registry (again similar to driving and registering your vehicle) that would establish chain of custody for all firearms in the United States.
That's an incomplete list, there's still mental health provisions and red flag laws that would also make obtaining a firearm legally more difficult for would-be wrongdoers.
With just those few things you
can dramatically reduce the amount of unregistered firearms available to criminals and make it harder for would be criminals to obtain them legally. (
https://www.google.com/amp/s/www.bbc.com/news/magazine-38365729.amp here's a country that took just those steps as a proof of concept of what can be done with enough political will.)
Now, if a criminal still wants to commit a crime with a gun then they may well go ahead and do so, but that's true of anything illegal. That doesn't mean that we shouldn't respond to the gun epidemic this country clearly has with sensible measures. That is a zero sum argument made by gun manufacturers that don't want to see a dent in their potential market.