Probably not. A feeder would have to be at least 7 1/2 ft. off the ground be out of bear reach, and bears can jump, I've seen them do it. If the feeder's mounted on a high metal pole like one of mine is, a bear can just push and bend the pole over.
Bears that become accustomed to raiding feeders become problem bears and eventually become dead bears. The idea is to give them an unpleasant experience around human habitation so they don't return. The rubber buckshot was issued to me by a wildlife officer.
Btw, I'm very careful to not leave feeders out or accessible after dark when bears typically forage. Don't want bear problems.