The Q&A information is from the ATF's web site here:
Originally Posted by Groovy Mike
The previous part, about federal law allowing the sale of a long gun or handgun is quoted on many web sites. It's here on Wikipedia, in the section on sales between individuals:
The first question on the ATF page also talks about the legality of selling to an individual.
Necessity is the mother of invention, and laziness is the father.