[Lurker]

I'd avoid DC entirely and take the scenic route through Tennessee, West Virginia and Virginia.

L

[George Smiley]

I think I'd be okay in Maryland courtesy of 18 USC 926A

It basically says that if you're going from point A where you can legally possess a certain firearm to point B where you can legally possess it, then as long as it's unloaded and not in the passenger compartment (or unloaded, in a locked container if you're in a car that doesn't have a trunk), then federal law says you have the legal right to do so.