500 Nitro,

There is a customs form which can be used as evidence that any personal property taken out of the USA was not purchased overseas, I forgot the number of it although the number that NitroX mentioned sounds familiar, and when I was working as an corporate pilot I had a copy of it on file because I did not want customs to charge me duty on my watches on return to the USA. Technically the form is not proof that you own anything, it is just proof that you had the item in the USA and did not buy it overseas intending to sneak through customs without paying the import duty. You could fill out the form for anything you own or anything you borrowed from someone else then file it with Customs and they won't question that item on your return.

Every time I've been outside of the USA I've used a borrowed gun so I'm hoping for some definite information on this question myself because I want to go hunting in NT too and I'd like to use one of my own firearms for once.

Still as a rule in the USA, unless you're selling land or a car or an airplane, all of which require a deed or title, you don't have to prove ownership of an item. What is in your possession is generally assumed to be yours. For those people who are up to no good, the police and prosecuting attorneys have to prove it is stolen.

Richard.