No ‘ he can’t do it legally. Private sales on hand guns must go to a dealer and run the back round check. It does happen I know but it is not legal.
"Some" (very few) states require that. Most don't. But it is still illegal for anyone with certain serious mental problems to OWN or BUY a gun--even though it may be legal for someone else to SELL one without a background check.
No they don't. Not by Federal Law.
That's the whole brouhaha over the so-called 'gun show loophole'.
Which in reality isn't about gun shows anyway, it's about private sales.