imported post
Your best bet is to just ask them. Make sure you bring something current to prove that you are a Utah resident as well, be it a current utility bill (I'd bring one thats at least 90 days old as well), bank statement, or something else with your name and Utah address on it. If you dont have anything like that, I think you're pretty much out of luck as you cant prove you're a resident.
As far as rules go, I'm not 100% certain, but I dont believe it says anything about a permanent or primary residence, but only being a resident of the state. You have a home in the state, so officially, you would be a resident.
The relevant laws are 922.a.3 and 922.a.5 (of 18 USC Chapter 44 of the GCA) concerning transfers to/from people out of state.
Also, 478.11 (of 27 CFR Part 478 of the GCA) defines state of residence if one has the intention of making a home in that state. That being said, in the examples given (example 2 specifically), if you have two homes in two different states, while in one of those states, you are a resident of the state you're currently in. (see
http://www.atf.gov/firearms/faq/unlicensed-persons.html#state-residency as well since it restates the law). I guess it really comes down to if you actually live in the Highland home at any time in the year or not. If not (ie no house on property, house is rented to someone else, parents house, or something else), you're stuck with buying the firearm in your own state.
If you do feel the law is applicable to your situation, you'll probably have to fill out the 4473 with your Utah address, since that would be your residence while you're in Utah. Ask them, as they'll know a lot more about it and if they're willing to do the transfer or not. I know the E-4473 (electronic version) allows a primary and secondary residence addresses, but I dont know of anyone actually using it. If you really feel ambitious, you could track down and print the above mentioned laws and regulations to show them if they're on the fence.
Legally, if you ever occupy the Utah house, they should be able to do the transfer, but ultimately, I think it'll be up to the FFL if they want to do it or not. I wouldn't push it if they say no though, as all it takes is the suspicion that someone is going to falsify the 4473 to be able to refuse the transfer, no actual proof needed. (Read the place the FFL needs to sign, saying they believe that the transferee answered everything truthfully. If they dont believe it and sign it, they'd be falsifying the 4473 themselves and breaking the law.)
Just be 100% straight forward, bring lots of id with the utah address, and you'll probably be good. Worst case is they say no.
If you (and the FFL) decides to allow the transfer, as far as registering when you get back to Cali, no clue. Does Cali have a gun registration? If so, then you'd probably want to get your firearm entered into their registration database as penalties for having an unregistered gun are probably high. You'd know what silly laws they have better than I would though.