General Firearm Discussion
UPS:
https://www.ups.com/us/en/help-center/packaging-and-supplies/special-care-shipments/firearms.page
"Handguns, as defined by 18 U.S.C. § 921, will be accepted for transportation only via UPS Next Day Air Services, specifically, UPS Next Day Air® Early, UPS Next Day Air®, and UPS Next Day Air...