Has anyone asked these companies how the stores get the rifles in the first place? I know for a FACT that many firearms and airguns are shipped via USPS, UPS, and FedEx. So for them to say that they don't ship anything firearms is a load of crap. Typically it will boil down to the individual location, as they are a franchise and not directly owned by the parent companies. This lets them dictate their own policies and what not.
Just tell them it is a piece of art, custom carved piece, pneumatic lead accelerator lab equipment. All are technically correct and if you have to file a claim you will be fine. Have had to file claims a few times and had zero issues getting my money out of them.