3" 5,6 or 7'sthe through at the least a full choke for turkeys. A farely tight pattern equates to knockdown. If ya don't have the bank to get an assortment of chokes or ammo. And your goin with a modified try federal heavy weight 7's. Plenty of pellets to 40 yds and definitely knock em to the ground. Good luck and pattern your gun at the range. You will have more confidence if your throwing shot at the paper targets, when a longbeard is standing between 30 and 40.