Not to split hairs but there are far more than 390 million guns in the US
Those numbers people throw around are based on records kept the last few decades and somehow forget that before then there were lots of guns
I’ve seen a credible estimate that there are between 850-950 million firearms in the US and that there are probably about 50 million lost or stayed away and forgotten
Sadly not enough ammo to go around. Bet 90% of these gunowners have less than a 100 rounds of ammo. I’m a 3%-er.