Sec 18 USC 926A. Interstate transportation of firearms.
Notwithstanding any other provision of any law or any rule or regulation of a State or any political subdivision thereof, any person who is not otherwise prohibited by this chapter from transporting, shipping, or receiving a firearm shall be entitled to transport a firearm for any lawful purpose from any place where he may lawfully possess and carry such firearm to any other place where he may lawfully possess and carry such firearm if, during such transportation the firearm is unloaded, and neither the firearm nor any ammunition being transported is readily accessible or is directly accessible from the passenger compartment of such transporting vehicle: Provided, That in the case of a vehicle without a compartment separate from the driver's compartment the firearm or ammunition shall be contained in a locked container other than the glove compartment or console.
Interstate travel with a firearm is, therefore, permissible as long as the firearm is unloaded and in such a place that it is completely inaccessible (preferably the trunk of the vehicle).
HOWEVER, IT IS STRONGLY RECOMMENDED THAT CITIZENS PLANNING TO TRAVEL WITH A FIREARM SHOULD CALL THE LAW ENFORCEMENT OR LICENSING AUTHORITIES IN THE STATES TO OR THROUGH WHICH THEY WILL BE TRAVELING TO OBTAIN THE LATEST INFORMATION REGARDING WEAPON TRANSPORT LAWS. IN SOME CASES, STATE LAW TAKES PRECEDENCE OVER FEDERAL LAW REGARDING INTERSTATE TRANSPORT OF FIREARMS.