FYI, it is NOT illegal to purchase a gun out of state in all states.
It shouldn't be in ANY state.
Either I'm a U.S. citizen or not.
It is unless the 1968 Gun Control Act has been repealed, and as a former FFL gun dealer I think I would have noticed if that had happened.
The restriction on out of state sales was lifted on shoulder fired firearms i.e., shotguns and rifles, in the 1986 revision of the '68 GCA IIRC. But unless the GCA has since been secretly repealed in total it is still illegal for any non-FFL gun owner to sell or transfer in any way a handgun to any other non-FFL who resides in another state. If you give your son a .22 pistol for Christmas and he lives in another state, unless you transfer the gun through a licensed FFL gun dealer in his state you just broke a federal law and the penalty is ten years in a federal penitentiary with no chance of parole. Of course the FFL charges for his service plus the background check fee and the shipping charge to his place of business, but that's just a tiny part of the price we pay for meekly allowing our Constitutional rights to be taken away by the elected fools and traitors who run this country.
BTW, you can thank LBJ and his Democrat rubberstamp Congress for that '68 GCA. IMHO LBJ did more to destroy Constitutional government in the US than any other man who ever held public office.
Sorry, but it's illegal to purchase a handgun out of state in all states unless the purchase goes through a FFL holder in your home state. If you circumvent the homestate FFL and take possession of the weapon in a state that you are not resident in, you have committed a felony.