Are you using this 10 gauge for turkeys? If so why not try #6shot.. especially if you can find it in heavyshot. Still carries the same knockdown power as #4shot but the pellet count is much higher. Alot of guys i now use #7shot in the heavyweight.. but I dont care for it. The heavyshot will hurt your wallet a bit, but I have found it to shoot extremely well no matter what what kind of choke/barrel combo you use. IF you dont want to spend the money on the heavyweight...
TRY THE FEDERAL FLIGHT CONTROL #4's... I love these things, I have a H&R 10 gauge and I have seen many different types of groups.. but if you want TIGHT groups try the flight control... I have had my wad stick in the paper at 40 yards! It leaves a tangerine size hole in turkeys and paper a like...Alot of people will say the pattern is TOOOO tight, but I have a red dot scope on my shotgun and I like to know whatever I aim at.. is going to die...