RE: the buckshot rationale:
20 feet is 6 meters - that is CLOSE. If I can't guarantee a kill or full bear stop with a skull shot at 6 meters with buckshot, then I shouldn't attempt such a thing. Especially considering I could have a rifle at my disposal which could break shoulders at the same range, let alone penetrate a few feet into the bear.
About the last thing I want is some wounded angry wounded free-roaming wounded one-eyed wounded grizzly that I would have to explain to the authorities, let alone one that would kill me for hurting it.
Thanks for your thoughts but I just can't see risking my life or endangering others by trying experiments like that.
I'm not asking for 'should work under the right circumstances'. I want to know what has worked and will work almost every time if I do my part. Brennekes seem like recommended bare minimum given collective experience. The .30-06 with heavy partitions seems a little better than the shotgun.
So buckshot is out of the question for me. I'm even wondering if I should bother with a shotgun. The .30-06 FWT with a 2.5x20mm or an Aimpoint Micro might be lighter, more powerful, more rugged, easier to maintain and maybe easier to work safely with.
There was an interesting Shockey episode on a few weeks' back where a 10 yr old boy dumped a huge, in Shockey's words, "He's as big as they get", black bear in its tracks from about 100yards.
The boy was using a .30/06 with 220gn Partition.