Yes, you can ship long guns by USPS. But not handguns, unless you are an FFL.
UPS and FedEx force you to pay Next Day charges for handguns. But it is not a Fed requirement. It is because they (say) that they do not want handguns sitting in their depots. They get pilfered there. They want counter-driver-customer speed. At least that's what they say.
AND IT COSTS MORE!!!
Mustang Gregg [FFL]
Wild West Arms
There is Form the
receiving FFL must send you with his FFL # , DBA Address & his Signature , with this in hand (yours) , a copy inside the package and a copy for the Post Office Clerk ( thats 3 copies)....
That's the instructions I got from my USPS Branch, pryor to and when they accepted a pistol being sent to the FFL.
Cost was $ 6.90 , the express mail box ( "if it fits, it ships" slogan ) included delivery conformation.
This is the same service a shipping FFL uses ( except he is charging you for his time )