Not sure if it's what you mean, but guns cannot be collected, the rules state you must take them to a Post Office.
You cannot "set the level", all you get is the basic level provided on the service you use, guns are excluded from any further compensation this has been stated dozens of times.
Being a little apprehensive about sending an airgun through "the post", I carefully read up on the process ie. Parcelforce 48 going through the fine print. On finding the relevent section regarding "low powered airguns" I printed it off and took it down to my local PO.
I know the people there very well but I couldnt help but see the slightly pained expression on the face of the Lady post mistress when I mentioned the word "airgun".
I then produced my printed sheet which she carefully read then she dug out "her paperwork" from behind the counter which confirmed all I had read and produced.
After that she was happy to proceed and I took an airgun down to be posted (PF 48 or 24) the next day no issues at all !
Moral of the storey is obviously to politely inform PO staff of the facts as it may be that posting an airgun is not something frequently carried out in many Post Offices or like many of us, they are simply not entirely aware of the " small print" !
“An airgun or two”………