I've seen hog kills with a Gamo air rifle, but there's nothing like the warm, fuzzy feeling of a 450b with a full mag...aahhh. With a 223, I'd be sure I was wearing my running shoes out there...
EDIT: Hey, that gives me an idea. We should develop a new 100-yard shooting sport: The "100-Yard Hog Dash"...for this one, you start down at the target frames, fire a shot into the bullseye, and then haul ass back to the shooting bench. Best time in full hunting gear wins!