I had to run an (extra) lower wire last year. A young bear was sneaking under my wire. I have a 20 mile charger on a 25 yard enclosure, so the "jolt" is substantial. It appears that once they get one pop, they're trained (30 years of experience, here).
The big resident boar is likely pushing 36" at the shoulder (three independent sightings said 4 feet - which I suspect is an exaggeration, but the "400#+" is probable).
Regardless, all the older resident bears seem to have learned that the taste of honey isn't worth the memory of getting knocked on their collective Be-arses, when they were younger. I have no doubt a wandering newcomer might go through it like butter, but it hasn't happened yet. The neighborhood dog pack alarms everyone when the bears are around, and "backup plans" (ie "bear medicine") let us all sleep with relative ease.