I had to educate my local USPS office on this matter.
It almost turned into an argument, but just be prepared to show them on their own website as well as the ATF website, and I don't see how they couldn't work with you then.
Now they are glad to ship rifles for me and they're quite a bit cheaper than UPS was.
I'd recommend seeing your local USPS, and honestly I don't understand why anyone thinks they need to hide what they're shipping or be shady about it. When I walk in now with a long box, they ask "Firearm?"...I say yep, no ammo, FFL info in the box. No fuss, no problems.
