For my own information :
Did I get it right : the differences between a BB air gun and a pellet air gun are mainly the missile itself (round steel ball vs lead pellet) and the barrel (smoothbore vs rifled barrel) ??
FYI, in France, air guns, which muzzle energy is over 10 joules, must be declared to authorities ("7ème catégorie")
Such air guns are not easy to find here.
I found
an english maker, but the prices he asks for his guns ... amazing... about 1900€, without VAT.
That's in the same range as a (very) good target .22LR carbine ( i.e. Anschutz).
I guess it has to do with guns laws in GB (Bentirran ?? what's your take on this ??)