I do not like the long beard 4s....just not enough BBs for my taste. I personally use 6s. I tried 5s and 6s and the 6s pattern the best with many different chokes I tried out to 50 yards. I do not advocate a 50 yard shot but I had an incident once where I thought a bird was at 40 yards (my max distance) in a field and he was at 46 yards. He was hit but wounded...but fortunately I was able to run up and give him a second shot. Now I pattern my guns to 50 yards and also at 15 yards (don't want a crazy tight pattern either) and whatever gives me the best patterns in both those cases is what I go with. A tighter choke does not always yield a better pattern at distance. If I were you...id buy 2 or 3 different sized "turkey" spec chokes and go give them a try for your distances you plan to hunt. Also, you never know when you might want to change ammo and having multiple chokes is always a good thing because different ammo will pattern better in different chokes.
