I ship/receive black powder revolvers and rifles by UPS all the time.
A lot, and I mean A LOT of people working in the industry are not familiar with the laws. And for many of them, this job is the only job they have, or can obtain in their area, so they DO NOT want to make mistakes. They rather be safe than sorry and risk losing their only income source.
BORDERLANDS: THE GRAPHIC NOVEL
A story about a man, his harrowing journey, a vast frontier, and a great struggle.