SxS patterns vary left and right with heavy loads and harder shot. A turkey head and neck are vertical. The usual thing is to set it up sighted in for one barrel and use an open choke for the other barrel. Others spend gobs of effort trying to get both barrels to hit close enough together.

An O/U works much better because they vary high and low. You can sight in for the head with both barrels hitting one on the head and the other on the neck.