Joe has a CCW permit from state A which allows Joe to carry a switchblade. Now Joe goes to state B on business. State A CCW Permits are honored by State B. However, State B does not allow it's CCW permit holders to carry a switchblade.

Is Joe covered by his state A CCW for carrying his knife, or does  State B's prohibition on knives apply to him while he is in State B?

I would guess that state B would throw Joe's ass in jail.

ETA why the hell are you wasting magazine space with a knife?

Think of it this way...my state does not require disclosure to LEO....I carry my CCW in another state with reciprocity and get pulled over. (this state happens to require desclosure)

I say nothing the officer regarding my weapon. After routine investigation they notice the butt of my weapon printing and draw down on me.

Follow the laws of the state you are in....if for no other reason because the LEO that are the first point of contact with the law expect things to be a certain way. They only know the laws in their state (hopefully) and probably have no idea what the reciprocity laws are with state X. If you can find a law in the state you are visiting that grants you exclusion, I suggest you print it out and have it in your wallet. Better to have the law as its written in your possession.

Carry what you can and stay safe.

The laws of the state you are visiting apply.

Excellent question and the answer is: The laws of state B hold sway.

Example: I have a FL CCW permit.  I can carry any concealed weapon on my person.  In GA, I can only carry a concealed handgun.  Also, since GA is more restrictive on places I am allowed to carry, I have to abide by GA rules of carry.

Go to Packing.org

State B's laws apply.  Same as if a Virginian went to NYC on business and tried to light up a cigarette in a restaurant.  "Oh, but I'm from Virginia!" doesn't cut it.

I have a WA permit, and went to ID on several occasions for shooting events.  The folks running the events in ID were careful to warn everyone that while their out-of-state permits were accepted there, they had to follow ID law regarding bars and so on.  (IIRC, in WA you can't carry in bars;  in ID you can, but you're not allowed to drink, or at least cannot become intoxicated.)

Y'all are substantiating what I figured....the laws of the state you are in are the ones that apply. So if Joe is crossing several states to reach his destination and both his home state and his destination state allow carrying a switchblade, can he lock it away just like you would have to do with a pistol in some states?

The states whose permits we honor, but don't honor ours really piss me off.

Think of it this way:

You have a drivers license that allows you to drive on the roads. State A allows you to go 75 mph, But State B has a limit of 55. Just because you have a license issued by state A does not mean you are allowed to drive 75 in state B - you will get a ticket.