There has been a fashion for 20 bores in England for driven pheasants for a while, supposedly for the challenge, although most 20s shoot loads equivalent to standard 12s now anyway. 28bores are becoming more fashionable and for a good shot, they are more than adequate for all but very high bird shoots (long range) such as some of those found in the southwest of England where you really should use 34 or 36 gram loads out of a longer barrelled heavier gun.