Founder,
You may ship a gun from you to you without an FFL.
You may ship a gun to an FFL for repair and they can ship it directly back to you.
If you're selling out of State, you must get a copy of the FFL for the dealer to which you"ll be sending the gun and send the gun to the dealer... not the buyer.
If you're buying a gun from an individual or dealer who is out of State, you must have the seller ship it to an FFL dealer here in your State. The seller/shipper will require a copy of your FFL dealer's license before they can ship.
Shipping regulations vary between shippers so check with them FIRST.
UPS hub will ship about everything but the fees vary depending on what it is.
Most UPS store will not even ship a gun part! azzwipes!
I've shipped/sold/bought dozens and dozens of times!
Zeke