$ That is a very very bad deal. Never heard of such a thing either. What was the reason given? I suspect a counter-monkey didn't know his or her own responsibilities and rules. Good to have copies of the stuff, which is easier to do these days than it used to be.
All of my ammo is not only handloaded, it is not available on the shelf anywhere in the world. Because it is all blackpowder, I have a some special documentation that I take explaining that it is legal to fly although loose bp as a muzzleloader would use, is not.
It is not hard to know more about these rules than the counter-critters at the airports, but convincing them carefully w/o getting the riled up, that is the trick. So far, so good.