Funny story, I had the opposite experience this morning. I was putting together a care package for a friend, which included a box of ammo for a rifle we'd enjoyed shooting together. I was just about to take it by the post office when I thought I'd check if I was supposed to mark it in some special way or something, and promptly discovered that this was ILLEGAL. With rather frightening penalties. But UPS would cheerfully take it.

This struck me as the most frighteningly bizarre, arbitrary and pointless rule I had heard in a long time, and I spent a while trying to fathom the logic of it.

I suppose it isn't really a surprise - laws surrounding weapons reflect two conflicting views and intuitions, on the one side that they are inherently scary and suspicious, on the other that they are unremarkable if handled responsibly. I wish our laws reflected a neighborly attempt by the two groups to live together and avoid unsettling the one and persecuting the other. Alas, they flip randomly between the one view and the other, managing to cause these issues for BOTH groups!