Shipping a firearm question.

First topic message reminder :

I sold my 52-2, shipp8ng it to a guy back east. I’m not going to ship through a FFL. I have the paperwork from the FFL I’m shipping to. I’ve read the UPS site on requirements for shipping a handgun. One of the reqs is to inform the driver or counter person that the box contains a handgun. Why? Do they treat it any differently, separate the package from the others? Secret stamp? The package can’t have any labeling that leads anyone to think there is a handgun inside. Does anyone know what the deal with that req is? 
Kurt

I wanted to follow up on how shipping my handgun turned out.
I e mailed the receiving FFL about the transfer. They sent me their FFL license and address to send it to. I used my business UPS account and printed a Next Day Air Saver label. It costed about $102.00 using a UPS medium box. Packed the gun and accessories, and an envelope with the FFL and a copy of my driver’s license. The UPS guy came and I handed him the box. I got a delivery notice the next day. Easy.  I asked another driver about telling him I’m shipping a firearm. He said it’s so they can separate it for getting an adult signature on delivery. So everything worked just fine. Now I know what to do for the next one.
Kurt

I thought I'd find my answer here, but I guess I'll have to ask:

UPS regs cited earlier in the thread explicitly address "licensed collectors."  USPS regs I have found simply state the "licensees" can ship ...  And my understanding is that a USPS flat rate box is the most economical approach.

So, assuming I am shipping to an FFL in another state, does my C&R, which says "Federal Firearms License" at the top, permit me to use USPS?

Yes it does.

It's not just UPS or FedEx requiring this.

ATF regs [18USC 1915, 922(a)(5) & 922 (a)(2)(A); 27CFR 478.31] state a non-licensee may only ship a handgun by common or contract carrier. A non-licensee may ship a rifle or shotgun to a resident of his state or to a licensee in any state by US Postal.