Call local Sheriff's Office
The best thing to do is to call the local Sheriff's office in the state where you want to carry a weapon; be it 'open carry', or concealed. When I went to Maryland a few months ago, I called with questions regarding carrying a revolver, and one person said I could not bring the gun into Maryland, permit or no permit. Another person said as long as the weapon is unloaded, and locked in either the glove compartment or the trunk, with the bullets in a separate place, I was fine. Since I got two different stories, I didn't take my gun at all. I will be getting my conceal carry permit in a few weeks, hopefully, and I know what states honor NC state's conceal carry laws. And it's a quite a few of them too. Maryland, NJ, and NY are a few that don't. But I don't travel that way often anyway. I like the south, and that's where I do a lot of my traveling.
<http://65.190.88.101/calibers/conmap.php>