Any blackpowder weapon is considered an antique pre 1898 and can be shipped to anyone over the age of 18
USPS allows longguns to be shipped with no problems at all. They just dont allow handguns.
For handguns, you have to use UPS or FEDEX with overnight air
I've shipped handguns to smiths and mfgr's both out of state and they shipped em back with fed-ex and ups. never overnight on any of them. hate to think how much that would cost. is that something new. shipped my sig 220 back and forth to sig less than a year ago.
Shipping of any firearm back to a manufacturer is a completely different animal. You can use FEDEX or UPS (any firearm) and USPS longuns and send them to the manufacturer/customizer/gunsmith anywhere in the USA and they can/will return it to your front door without the use of an FFL on your end. That is probably one of the only exceptions I know of. I have sent many firearms back to the manufacturer or gunsmith and had them returned to my front door after they rectified-completed there work.
I used to use a guy in Iowa to do complete Hot Blueing for $75 per gun plus shipping $20 and would ship directly to him and he would send it directly back to me. Did probably 5-6 guns between me and a couple friends, but he retired in 2003. Now we use a Smith in GA who charges $150 per gun for complete and proper Hot Blueing.
I don't have an FFL and I have bought several guns from Track of the Wolf in Minnesota and several from Tenessee Valley Muzzleloading in Mississippi.....
