I think the number is about 150 million NICS background checks since Obama was elected. I don't know if I am typical or atypical, but the last time I made a purchase, I bought 3 (three) guns at the same time, on 1 (one) NICS background check.
This study is silly.
My own guesstimate is that there are at least 450 million firearms in private hands in the country.
I haven’t made multiple purchases on individual NICS background checks, but I will say that I’ve had five or more such background checks in Obama’s second term alone.
I reckon you’re about right. Add in all those home built projects, the illegal imports, and the various multiple sales recorded as one NICS transaction and you’re talking a lot of firearms.