And as I stated in post#14, because there isn't an answer the manufacturers appear to be hedging their bets by making sure that one or the other applies,
It simply avoids a "12fpe rifle" that fails both, suddenly falling foul of the law because some tw*t decides to cut the stock & hold it like a pistol.
It's called "erring on the side of safety",
https://assets.publishing.service.go...l_2016_v20.pdf
Page 13 para 2.46 seems to confirm exactly what I am saying by clearly stating "any air pistol which has a barrel less than 30cm in length
or is less than 60cm length overall with a muzzle energy in excess of 6fpe is a prohibited firearm"
Therefore by having one
OR the other the pistol/rifle definition becomes moot up to 12fpe.