7, 7.5, 8 and 9
In a 28g load. 7's are best for Pigeon in my opinion, an excellent pattern, and more than enough power to Kill a very soft feathered bird like the Pigeon.
If it will Kill a Carrion Crow, then it will kill a measly Pigeon.
Regards
SS
P.S And yes, I do use 7.5, 8 and 9, nothing wrong with them at all.