If memory serves, the exemption for a returning US Citizen is not to exceed one kilo of loose tobacco. Having said that, I can't recall anyone ever writing a duty or IRT ticket for pipe tobacco. Cigarettes are another story altogether. That is something CBP will zap you for for each carton above your one carton limit. Bear in mind, this is based on my nearly 18 years at JFK Airport in NY. I can't speak for any other airport. Your best best is to call the airport you will be arriving at and ask if the have a "Ship's Office' and ask to speak to the CBP Officer on duty. Generally, most major International Airports have an "expert" who can guide you as to what they will allow in and what they will 'write for". As long as you claim it on your 259 form, there would be little they can do as far as seizing it since you "legally declared it". Remember, you also have to stateyou are a "returning US Citizen" and the tobacco is strictly for your personal use! If you brought it out with you to Germany when you initially moved over there, you would have to separate what you brought over from what you are bringing back (acquired abroad). Good luck and always remember, honesty is the best policy when dealing with CBP Officers. Most could care less about pipe tobacco. They are looking for contraband and high dollar undeclared items (ie: Rolex Watches).