Japan is a large, rich country that has virtually eliminated gun deaths.
More detail:
https://www.businessinsider.com/gun-control-how-japan-has-almost-completely-eliminated-gun-deaths-2017-10?amp
Try these steps — if we implement all these steps (*all* of them, no cutting corners), allow time for these changes to take effect, and it *still* doesn’t work, then go back to the drawing board and try something else. That would be a rational, evidence-based way of approaching the subject, if we were serious about this as a country.
South Korea is another model.