Iirc there was a change in the wording of the mv & me section of the definition of airguns that placed them within or without the fa. I had not enough time to read further. This am over a cuppa it looks like a lot of opinion is mixed in there.
This was from a few years back when the bogeyman was not baby killer pocketknives but the plastic jacketed air rifle pellets with zn (?) or was it steel busines ends, which the authorities were in a tizzy about. Approx, 10 yrs ago? The media tizzy is long gone yet we are stuck with more bumfodder laws until hell freezes over.