Can't get an AR here in California,

But a few hundred miles east there is a lovely state known as Nevada that will sell me anything I want, IF I'm a resident.

The BATF's site says establishing a residency is moving to a state with the intention of making a home there....

But what do I need to prove that I'm a "resident" ?   Driver's license?  Rent receipts?  

You have to live in the state for 6 months and actually have a residence. Just having a P.O. box will not do.

Each state is different on what constitutes residency, and it varies depending on what you're trying to do.

Most states seem to require 90 days to establish residency for firearms purchases, but some are 6 months.  There might be some where just buying property and declaring you're a resident would do it.

You can actually have dual residency - say, purchase a vacation home in Nevada, and you are entitled to purchase guns there as a resident during the actual time you're in residence there.  You'll generally need a valid form of ID, and since most states make you surrender your former license when issued the new one, you could get a non-driving state identification card with your in-state address for your purchases while in residence there.

Nevada is unusual in that for purposes of obtaining a DIVORCE you have to live in the state just six WEEKS and get an affidavit from another individual who has been a resident for at least 12 months.

For claiming residency for TAX purposes it's a lot more complicated.  I won't even start down that road; expert advice is required.

But to obtain a Nevada driver's license (which should be sufficient to purchase a firearm), there is NO minimum period.  You have to provide a physical mailing address (not a P.O. box) and surrender a license from another state.

According to the Nevada DMV site:

"New residents must obtain their Nevada drivers license and vehicle registration within 30 days."

See [url]http://www.dmvstat.com/[/url]

They probably issue a tissue paper temporary license on the spot.  It probably takes a couple of weeks before they mail out your permanent picture ID.  There may be a length-of-residency requirement in the state firearms laws.  I haven't tried to look that one up.