I am curious: I wonder if ANY hiker on the JMT or in the Sierra anywhere has actually been successful using pepper spray on a bear. I think that is pretty unlikely.
Steve, define what you mean by success?
I would call it successful if they were actually able to hit the bear with the stuff, enough to cause it to change course or whatever it was doing that the human wanted it to stop.
I am thinking it would be pretty difficult to even get close enough to a Sierra bear in order to spray it.