I can give you a more definitive answer than that. The requirement for the two states to be adjacent to each other was done away with in a 1986 amendment to the GCA of 1968. A person can purchase a long gun in any state other than their state of residence - only from an FFL, so long as the sale would be legal in both the state the selling FFL is located in and the state of residence of the purchaser, and all the laws of the seller's and buyer's states are complied with. And that is why all the talk of the anti-gun crowd about the "gun show" and "internet sales" "loopholes" are completely false. Such sales that cross state lines must go through an FFL with the required form 4473 and background check.