I've been studying the state firearms transportation laws but even the interpretations seem vague.  So I'm not quite sure if it's legal to transport an encased rifle (unloaded, action open of course) behind the seats in the extended cab of a pick-up truck.

It can be loaded or unloaded as long as it is plain view.  Cased is considered "in plain view" as long as appears to be a gun case.  Don't use a gym bag, guitar case etc.  

Hidden behind/underneath the seat of a truck... I'm not sure.  Can you (or any other occupants) get to it without stopping and getting out?  If so it had better be unloaded.  

Basically if it's in the open you're good to go loaded or not.  Our laws are confusing as shit and not spelled out very well.  Knife laws are even worse.  Our laws leave too much to officer discretion IMO.

ETA:  If you really want to hide it from view I'd have it unloaded and the case locked.

Interesting.  I was focusing more on the accessibility aspect, so I was planning on putting a bunch of stuff on top of the gun case to make it completely inaccessible while driving.  

But it sounds more like I need to keep the gun case in plain view.  

Thanks for the reply.

Unloaded and locked case with stuff piled on it you'd probably be gtg.  That's JMO though.

Yeah the laws in NC are confusing and often contradictory, any firearm in a locked trunk and out of reach of any passengers or readily visible inside the cabin (loaded or not) is ok. I have heard some reports of people being charged with illegally concealed firearms because they had them concealed in the back of a SUV with access to the passenger compartment, but I think those cases were extreme and probably teh result of something else going on during the search. I doubt any trouble would come from transporting a firearm in a locked case even if it was hidden from view but better to not chance it.

on a side note don't forget this:

Informing Law Enforcement of Carry:
The permit holder must carry the permit, together with valid identification, whenever carrying a concealed handgun, and is required to disclose to any law enforcement officer who addresses or approaches the permit holder that he or she is a permit holder and is carrying a concealed handgun.


http://www.usacarry.com/north_carolina_concealed_carry_permit_information.html

Yes, good point.   I have been aware of the duty of inform LE/Wildlife Resources of CCW while in NC since I do a good bit of fishing on the other side of the state line.  

First time I'm travelling with a long gun through your fine state though.  

I doubt you'll find an LEO in the state that will get pissy about an unloaded gun in a rifle case anywhere in the car/truck.