Open sight and with good eyesight, your effective range is going to be in the 100-yard neighborhood. Add decent optics and you can double that. Given the trajectory of this caliber, hitting a 6" diameter target beyond 200 yards becomes a crap shoot, which should be undesirable in anyone's hunting ethics.
Whithin the limits of its range, the 30-30 is a very capable deer-killer. If you are going to be hunting open country that regularly offers 150+ yard shots, I would consider something with a better ballistic trajectory. Otherwise, the 30-30 will bring home your venison.