What about shipping to states that classify airguns as firearms?

If you are shipping to NJ, RI, or to a buyer in Illinois with a regulated airgun (above .18 caliber AND 700 fps), the destination state treats the gun as a firearm even though federal law does not.

Best practice is to ship through an FFL on the receiving end, just as you would a firearm, and to confirm the buyer's eligibility before shipping. NYC requires a license to possess, so shipments to NYC addresses need extra scrutiny. When in doubt, route through an FFL - it is the safest path.