I think I've used about every shot size from OO buck up to 7 1/2 and they'll all kill a gobbler.
My favorite used to be 3" Federal 6s in 12ga. Then I discovered 3" Hevishot 4s which were dynamite, and should have been at $3 a round. Used 2 3/4 Remington pheasant loads with 7 1/2s for a bit, patterned great out of my old gun.
This year the Mrs has her gun loaded with Fiocchi Golden Pheasant 3" 1 5/8oz nickel plated 6s and I used 2oz of Bismuth 4s out of my SP10 on my first bird of the season. I will probably try for the next one with one of my Browning double autos and a pheasant load left over from December. That'll probably mean a 1 1/4oz load of 6s as I think that's what I have left.
