ORIGINAL: Rob/PA Bowyer
If you can get them busted up, calling is more effective come fall/winter. They want to be together. Like MoHo said, if you know where they are, get in tight and see what happens, if you know where they come and go, get between there and if they are out of range, run at them and bust them. Sit and listen for them to call to get back together. There is nothing like being in the middle of a bunch of turkeys who want to get back together. You'll learn more vocalizations than any other time in the woods.
I agree on busting them up! They will call and call to each other until they are back together again! I did this earlier this fall and called a couple in close but no Bowshot!