Just to place things in perspective, The type of shotgun and it's dependability is important but it must be fed good ammo also to be effective.
My choice for dangerous game (Like Bear) would be 000 Buck shot
because of the number of .36 caliber hits with one shot. The chances of hitting a vital area with 10 - 70.6 grain 36 cal bullets are much better,
and with 5 rounds that's 50 chances compared to 5. No doubt the slug has more energy but in a panic situation chances of a less than lethal
hit are much greater.
I have killed charging Hogs with a shotgun and it was very effective at stopping a very ****ed of animal intent on hurting me in there tracks.
So my recommendation is to pick the best weapon for your needs and feed it the best ammo. Your life may depend on it.
Just my opinion
J E CUSTOM
Ultimate Bear Defense Ammo:
If you've read this Thread, you already know I choose and use a Rem 870 shotgun as my bear defense firearm.
For years, the best ammo for my bear defense use was Brenneke slugs. And in factory shells, they are very capable bear stoppers. Even with solid torso hits at the close ranges where defensive encounters occur. Slugs are a single projectile and require good marksmanship to nail the target. When defending against charging bear, I want every advantage I can get. After all, the loser ends up dead, as often as not.
Tungsten (TSS) buckshot are the ultimate bear defense round for my needs and use. I now have a source for #4B, #1B, and #0000B TSS buckshot. I've already pattern tested the #4B and #0000B. Patterns are good for bear defense with the proper choke. A friend in FL and here in AK have also done some pattern testing. My preference has been #1B or #0B in my 12ga. My supplier is now making #1B available, and I will be pattern testing it in the near future.
Penetration: Throw away everything you know or ever knew about lead buckshot penetration, when thinking TSS penetration. My pattern testing was @ 25yds. TSS #4B penetrated live birch trunk 2", and #0000B penetrated 4".
My FL friend will be shooting FL hogs with TSS #4B and #1B as time and hogs allow. Our supplier ran ballistics for him on the #4B through a shotshell ballistics program. TSS #4B is projected to penetrate 8" of ballistic gel @110yds from a starting MV of 1,200fps. 110yd retained velocity of ~765fps.
I hope I never need to stop a marauding or charging bear. But I feel certain TSS buckshot gives me the highest odds of survival.
Bad part of it is, TSS buckshot must be reloaded, and it's pretty expensive to pattern test. However,
I consider it a bargain compared to medical bills - or worse...