This is a good place to start for anyone traveling:
Handgunlaw.us
Here's a book with some good info, although printed pages can't keep up with changing laws.
Gunlaws for the 50 States
There is no Federal law prohibiting you from carrying in a CMV. However you have to obey any local laws. And for that you had better do your homework! Anything from how it's stored and secured, mag restrictions, duty to retreat, when and where deadly force can be used. Even if you don't have a CCW permit there are provisions to transport a firearm, but if you have to use it, you had better know the local laws or a great lawyer.
As stated above you may also be restricted by your employer. In case you didn't believe the lies perpetuated by the trucking companies about Federal laws, many of them have their own rules in place.
Another issue also mentioned is where you are picking up and delivering to. Many places have signs prohibiting weapons. You may get in and out with no problem at these places. However I have been on Military bases where they searched my cabin with some type of device, not sure what it was but I was glad I didn't have any guns OR ammo.
You don't say if you are company or O/O. Obviously a company driver doesn't pick their own loads or make the rules. Whichever you are be safe out there!
