http://www.fedcoplaw.com/html/federal_firearms_laws.html
13. Transferring Personal Firearms (sell, give, loan)
a. A resident of a State may transfer a firearm to a resident of the same State.
1) But may not transfer a Hand Gun to a person under 18 years of age, § 922 (x)(1), 1 year or 10 years; see exceptions, § 922 (x)(3).
b. A resident of a State may not transfer a firearm to a resident of another State, § 922 (a)(5), 5 years, but ...
1) May transfer a firearm to a non-resident via a Will or intestate succession (no Will but State law describes division of estate), § 922 (a)(5)(A). May loan or rent a firearm to a non-resident for temporary lawful sporting purposes, § 922 (a)(5)(B). May send or deliver a firearm to a non-resident by first delivering the firearm to an FFL in the recipient’s State; the transfer would then take place at the FFL’s premises, § 922 (a)(1)(A).