I started free ranging mine (now 16 weeks old), about a month ago. I am still watching them while they free-range. They do not go far yet. Most of the time, they stay close together and close to the coop. If one runs home, they all do. I imagine they will start venturing out further as they get more comfortable. My 7 will return to the coop, then free range, going back and forth several times during an outing. I let them out for about 30 minutes, during my lunch break and again after work (3pm ish) for another 30 minutes or so.
How many do you have? Are they all pretty good about returning to you when called?