From the BATF site,he,the buyer would have to go to a dealer,it cannot be done by unlicensed individuals;
http://www.atf.gov/firearms/faq/unlicensed-persons.html#gca-unlicensed-transferQ:
To whom may an unlicensed person transfer firearms under the GCA?
A person may sell a firearm to an unlicensed resident of his State, if he does not know or have reasonable cause to believe the person is prohibited from receiving or possessing firearms under Federal law. A person may loan or rent a firearm to a resident of any State for temporary use for lawful sporting purposes, if he does not know or have reasonable cause to believe the person is prohibited from receiving or possessing firearms under Federal law.
A person may sell or transfer a firearm to a licensee in any State. However, a firearm other than a curio or relic may not be transferred interstate to a licensed collector.
[18 U.S.C. 922(a)(3) and (5), 922(d), 27 CFR 478.29 and 478.30]
Q:
From whom may an unlicensed person acquire a firearm under the GCA? A person may only acquire a firearm within the persons own State,
except that he or she may purchase or otherwise acquire a rifle or shotgun, in person, at a licensees premises in any State, provided the sale complies with State laws applicable in the State of sale and the State where the purchaser resides. A person may borrow or rent a firearm in any State for temporary use for lawful sporting purposes.
[18 U.S.C. 922(a)(3) and (5), 922(b)(3), 27 CFR 478.29 and 478.30]
The buyer has two options.
A) Come to your state and you go through a dealer there
B) Ship it to a FFL in his state and let him do the 4473 (and NICS call) there
