There's a great deal of misunderstanding regarding this topic, and I've been approached by several members of AA to make a post about it. These rules apply to "firearms" as defined in the Gun Control Act of 1968.  

If you wish to transfer a firearm to someone who lives in your OWN state, the Federal government has no jurisdiction, and you may do it any way you like, consistent with STATE law.  The Feds ONLY control INTERSTATE transfers, defined as transfers between residents of DIFFERENT states.

If you plan to transfer ownership of a GCA68 "firearm" to a person who is a legal resident of another state, you MUST use a holder of a Federal Firearms License (FFL) to do it.  Usually this will be a dealer with a class -01 license.  This applies to ALL GCA68 firearms, long guns and handguns both.  This transaction must be performed at the dealer's licensed premises or at a gun show in the same state as his licensed premises.

A dealer in MOST (not all) states is permitted to transfer LONG GUNS ONLY to non-residents if the sale is legal under state law both where the dealer does business and where the individual lives.  This applies only to long guns, NOT handguns. Handguns can ONLY be transferred to a resident of the same state in which the dealer does business.

Individuals MAY NOT knowingly transfer ownership of any GCA68 firearm to a non-resident of their state.  Even if it's your grandson, if he lives in another state and is at your home for Christmas you may NOT legally just hand him a gun as a gift.  You MUST use an FFL for the transfer to be legal.  You MAY NOT go to his home and transfer it there.  It is an INTERSTATE transfer in either case.  If your grandson is of age and lives in the SAME state you can do this.

Any GCA68 firearm manufactured more than 50 years prior to the current date may be transferred directly to the holder of a "C&R" (Curio & Relic) FFL, but note that a C&R licensee may ONLY receive C&R firearms in this way: if the gun isn't C&R he MUST receive it from an -01 licensee. Any gun manufactured BEFORE 1 January 1899 is legally an "antique" and is specifically exempted from the GCA by statute. 

ONLY an FFL can transfer a "firearm" covered by the GCA68 between residents of different states.  You may NOT legally do it in any other way.  Anyone who tells you something different is wrong.