Yes, if a company is an authorized shipper for UPS, then they accept the shipper's packaging. But, the issue seemingly ignored by all, is FRAUD! If you lie about the contents, and an insurance claim review reveals it, there are several potential damaging consequences. Just be sure that you're making an informed decision.
If listed as sporting goods, or a BB gun, or a toy, where is that fraud?? Now if you claim a vase then yes!! I never recomend fraud nor have I ever commited fraud. On one my claims I used machined parts as I only shipped a partial action, no stock. I always take pictures and used them for the ins claim...no issues !! Because a company does a volume business, they are entrusted to follow the rules...UPS does not rule out airguns, only restrictions are for hand guns!! very little restrictions on long guns but handguns require next day delivery. It is the individual franchises that restrict what they ship not the main shipping company!!! You are required to follow federal regulations....the most important one is ANY type of gun cannot be loaded, even our airguns follow that rule. I have worked for many different tool shops over the years, employees were always allowed to use the company shippers, most ofvthe time shipping was as much as 30% less expensive!!