The odd thing is that RM and PF have really complicated regulations, that their staff don't seem to know and get twitchy about. But then you have other couriers, like My Hermes, who doubtless ban all shooty things, but just turn up and take a parcel, no questions asked, and deliver it. So RM/PF quibble over air pistols, but their competition would apparently deliver a bazooka, no questions asked.

(NB - I do not own, and have not owned, and nor have I had someone courier on my behalf, a bazooka.)