I found a video on an ARFCOM thread of a man shooting a pissed off charging boar with a .45 caliber 1911. This a strong reminder of why handguns are poor at stopping dangerous flesh-and-blood things. ***Warning: Graphic. Lots of blood.*** -- turn it off after the first 20 seconds if you don't want to see blood spewing everywhere, but want to see the pig shrug off half a dozen rounds from close range.
A buddy and I once walked up on a huge boar in a field one day next to a jobsite; I had my 1911 in my hand and was aiming at it's head while it walked up to us within about six feet, curiously. After it got a gander at what we were, it wandered off back into the woods from where it came from, unimpressed, and I swear I heard it snort "Pffft! Sissies don't want nonna this!"
You've probably heard that .45 ACP knocks grown men clean off their feet with one shot up hill in the snow both ways, but that's clearly not the case even if you don't believe in physics. Keep shooting the beasty until it drops!! And when it comes to large, dangerous animals prone to charging, I would stick with rifles or arms that fire projectiles measured in ounces!
And sorry about the lite posting. I spend about six hours in traffic today, and there may be much more of that in my future.