TapRackBang
Cheaper Than Diamonds
If you do not know about dual residency, it is not wise to guess.
I agree, you should not guess about dual residency. There is no such thing except for narrow exceptions for military, and even narrower exceptions by the ATF for college students (as provided by WeiShen).
Outside of those, you can't have dual residency in two states.
From: http://www.residencyhq.com/dual-residency/
Dual residency in multiple states within the US borders is a sought-after and highly prized status. When investigating how you can be a resident of two or more states at one time, you may find suggestions that the process is quite easy. Or you may hear from a friend or neighbor that they are currently doing it, and have had no problem. The issue surrounding dual state residency, is that quite frankly, it is a myth. No one person can legally be a resident of two or more states at any given time.