yes, the key is the laws of your state...in this case it looks like Nevada for you...
the sale of ANY firearm to an individual from another state must be from a licensee
(this is commonly confused, people think it is ok for a private individual to sell a rifle to someone from another state...it ISNT..federal law dictates that only a licensee may do this)
For sales to residents of the SAME state though, its different....here in Virginia, for example, really all it takes is a handshake....(you cannot have knowledge that the person is otherwise disqualified, basically, from another state, a minor, or a felon...but you are under no affirmative duty to perform a background check to determine this)....
So, literally, at a gun show, I can walk in with a handgun, someone can walk up to me and offer me money, and off it goes....(I usually will, at the very least, ask to see a VA driver's license, but again, by VA law, I am under no obligation to do this)....if I did this very same thing in California though with a Cali resident I would be in deep, deep do-do....
another great resource is packing.org...it has a lot of the resources from the various states, Nevada included