Regardless of what you shoot them with, always take head/neck shots on hogs. I have shot several with my 7Mag and blew out their hearts and they still ran a good distance. With head or neck shots, they are usually DRT and you don't have to track them. Where I hunt hogs you can often shoot one and let them lay, and the others will come back out in a few minutes allowing another shot. If you don't drop them where they are standing though, you have to get out of your stand to go and find them and you scare the rest of them off.. This has been my experience. I guess the most important thing is to practice a lot and be certain of your shooting abilities.
Once you reach a point where you are a decent shot, you can head/neck shoot them with a .223 and they will fall right there.