I have shipped one long gun via USPS - but that was less fun...it was a bad receiver that needed to go back to the MFG for a known tolerance issue.
For a good chance at selling "oddball" chambered weapons - the more eyes that can see it - often the better. And I would not be surprised if there are more than a few on this board that would love that rifle.
Right now my taste is sort of drawn to the Long Ranger series by Henry Rifles. One of the ones that is a lever action + magazine in 308 or 6.5. No real plans on getting one, mostly because of a lack of places to hunt white tail deer.