Having just watched this program from Fieldsports Britain, it should help dispell some myths on steel shot.
The wads were what interested myself, the Eley ecowad and the Gamebore biowad both failed to open out on leaving the barrel. Jason Doyle then compared them pulling the petals apart snapping the little bits that hold the top of the petals together. He thought this was better than paper shot cup that fully opened out and was breaking up, I wish on such a program they were better educated as many will way h and think shot cups are simply to stay as an unopened cup.