You guys are a little bit mistaken....Here in Communist California if you LEGALLY registered your assault weapon, you can take it to any gun repair facility (gunsmith). Read on:
CA penal code section 12285(c) reads: "A PERSON WHO HAS REGISTERED AN ASSAULT WEAPON UNDER THIS SECTION MAY POSSESS IT ONLY UNDER ANY OF THE FOLLOWING CONDITIONS UNLESS A PERMIT ALLOWING ADDITIONAL USES IS FIRST OBTAINED UNDER SECTION 12286:"
Then it goes on. Read down to section "(7)" of the code:
12285(C)(7): "WHILE TRANSPORTING THE ASSAULT WEAPON BETWEEN ANY OF THE PLACES MENTIONED IN THIS SUBDIVISION, OR TO ANY LICENSED GUN DEALER, AS DEFINED IN SUBDIVISION (C) OF SECTION 12290, FOR SERVICING OR REPAIR..."
Now, if you're wondering what section 12290 says, specifically for "smithies" , read on:
12290(b)(1): "ANY LICENSED GUN DEALER, AS DEFINED IN SUBDIVISION (C) MAY TAKE POSSESSION OF ANY ASSAULT WEAPON FOR THE PURPOSES OF SERVICING OR REPAIR FROM ANY PERSON TO WHOM IT IS LEGALLY REGISTERED OR WHO HAS BEEN ISSUED A PERMIT TO POSSESS IT PURSUANT TO THIS CHAPTER."
For gun smiths, they need a dealer's license, and a business license. (12290 (B)(i) & (ii).
You can also ask "Bolsa Gunsmithing" in Westminster, CA (Orange Co) or King's gun works in Glendale (L.A. County). I believe they can also repair AR-15's.
So far, every gun dealer I deal with, all have permits to possess and sell out of state assault weapons AND take possession of your weapon for repairs, provided it's registered.
(ARM USA, Fullerton CA, Orange Co; Bolsa, etc...)