Depends on the quality/quantity of available food sources in the area they are being `free ranged'. Several square miles of good quality mast (plenty of acorns/corn fields/etc) and it could probably be done. Any droughty July/Aug with decrease in insects/grass seed heads/etc. and those turks will adjust the size of the range to meet their nutritional needs. Frequently famished turks will go rogue.
Ours eat a significantly smaller quantity of the commercial feed during the late Spring-early Fall but, in order to keep their minds focused on remaining in place, we always have the feed available and easily accessible.
Any dark marked heritage turk would do (RP's, etc. attract preds unduly).
Also, ranging without fencing (depending on your location) can also result in some turks taking off with the local Wild flocks/genetic pollution of Wild flocks (usually against the law - check TN regs). If your turks are hatched by you, or you get them as day olds and keep them within sight (brooder in the house so they see you all the time), during the first few weeks, they'll tend to be more `domesticated' and less likely to skedaddle with any wild interlopers. We have two-three wild flocks that cycle through our property and our turks are intimidated and standoffish, rather than tempted, by gobbling `siren-songers'.
