I have seen a couple dead elk from 3" 1oz rifled foster......enough that I started carrying mine for real brushy elk hunts that I know shots are going to be 50 yards or less......they flat work awesome for this and elk are big mean animals.
When I was in Alaska the 12 gauge slug was THE defensive choice. I spent 2 weeks on wildfire spike camping. The protection made available to us through the Alaska State Forestry warehouse system was Mossberg 500's and the only ammo choice was slugs.....these people been doing this for a long time.
We would get transported up and down rivers, Alaska roads, and all the boat drivers packed shotguns….yep with slugs
Anyone who says they don’t use them is purely for personal preference, those who say they won’t work have no exp with dangerous animal country