I have one. Can't vouch for them all, but mine rarely will range over 100 yards. Even then, it has to be something like a sign or building. Ranging in the woods from a stand, with trees, the ground or other normal forest objects, best I can get out of it consistantly is around 30 yards. Inside 30, it works ok. So, for bow hunting, I guess it is ok. But if you want one that consistantly works past 50 yards, save your money and buy a better unit.
Hank