According to ATF regs (Does not preclude State regulations)
Q: May a nonlicensee ship a firearm through the U.S. Postal Service?
A nonlicensee may not transfer a firearm to a non-licensed resident of another State. A nonlicensee may mail a shotgun or rifle to a resident of his or her own State or to a licensee in any State. The Postal Service recommends that long guns be sent by registered mail and that no marking of any kind which would indicate the nature of the contents be placed on the outside of any parcel containing firearms. Handguns are not mailable. A common or contract carrier must be used to ship a handgun.
[18 U.S.C. 1715, 922(a)(3), 922(a)(5) and 922 (a)(2)(A)]
Q: May a nonlicensee ship a firearm by common or contract carrier?
A nonlicensee may ship a firearm by a common or contract carrier to a resident of his or her own State or to a licensee in any State. A common or contract carrier must be used to ship a handgun. In addition, Federal law requires that the carrier be notified that the shipment contains a firearm and prohibits common or contract carriers from requiring or causing any label to be placed on any package indicating that it contains a firearm.
[18 U.S.C. 922(a)(2)(A), 922(a) (3), 922(a)(5) and 922(e), 27 CFR 478.31 and 478.30]
Q: Are curio or relic firearms exempt from the provisions of the GCA?
No. Curios or relics are still firearms subject to the provisions of the GCA; however, curio or relic firearms may be transferred in interstate commerce to licensed collectors or other licensees.
Q: What record-keeping procedures should be followed when two private individuals want to engage in a firearms transaction?
When a transaction takes place between private (unlicensed) persons who reside in the same State, the Gun Control Act (GCA) does not require any record keeping. A private person may sell a firearm to another private individual in his or her State of residence and, similarly, a private individual may buy a firearm from another private person who resides in the same State. It is not necessary under Federal law for a Federal firearms licensee (FFL) to assist in the sale or transfer when the buyer and seller are “same-State” residents. Of course, the transferor/seller may not knowingly transfer a firearm to someone who falls within any of the categories of prohibited persons contained in the GCA. See 18 U.S.C. §§ 922(g) and (n). However, as stated above, there are no GCA-required records to be completed by either party to the transfer.
There may be State or local laws or regulations that govern this type of transaction. Contact State Police units or the office of your State Attorney General for information on any such requirements.
Please note that if a private person wants to obtain a firearm from a private person who resides in another State, the firearm will have to be shipped to an FFL in the buyer’s State. The FFL will be responsible for record keeping.
Also, there is a place online to check the validity of FFL licenses IF YOU ARE ALSO a license holder. Does not help me but it might help some of you.
http://www.atf.gov/applications/fflezcheck/