My Benelli with Winchester #4 -3 inch - 3.5 was a waste of money - patterned real nice and I added a Hastings 0.663 choke.
I tried heavy shot and was not impressed.
But you will want to try different loads and establish you Maximum yardage. Just my opinion though - anything over 40 yards - well you are missing what turkey hutning is really about. Call the bird up close and personal!
Am proud to say to date - for the number of birds I have taken - my average is 22 yards.
JW