I saw a cool video on testing the safety of ammo, run over, burnt, all sorts of things. In short its probably safer to ship than a can of cheese wiz..
Funny my ammo gets shipped and is dumped on the front steps without even a knock on the door. An order of plastic magazines on the other hand? Adult signature required and I can't even sign a form giving consent to leave it, almost always a takes a trip to the post office a day later - I guess a child could chew on the plastic.