I went to post an air rifle this morning at my local post office. The gun was well packed and in a box that I once got a new S400 in. I passed over the parcel to be weighed and told him Parcel Force 48 please. He asked what's in there and I said an airgun for sporting use. He said and you want PF48 and I said well that's the only way I can send it. He said "are you sure, I didn't know that". This was the post master and I know he's been there a good number of years.
This is Thur a.m. so I asked if they would get it Sat a.m. He said "no" "they don't deliver sat. it will be Mon a.m.
So PF48 means PF96, (yes 4 days) if its posted Thur or Fri and you could probably send it how you want as P.O. staff don't know much about them although insurance may be a problem.