 There's certainly a lot of debate about that. There's a well-known Alaska bear guide who shot a huge grizzly with a 9mm and killed it. Does that make the 9mm the appropriate grizzly defense round? I probably wouldn't trust it to do that, but he ended up certainly making that work. If, on the other hand, you're thinking, hey, I'm going to use it for small game hunting and I don't want to alert anything in the woods...