I have used a .223 on pigs for quite some time. With no real issues. It is like some one said earlier. You have to place your shots. Dont expect to shoot one in the rear and it to come out the front. I have never had an issue, as long as I go for certain kill shots.
Ill try to find the memory card today that has some of my hunt pics on it. I have taken some big hogs with my wittle .223.
Eventhough I do not intend on shooting steel cased ammo (I am primarily going to hunt with my new AR) It is comforting to know that I can slap in some el cheapo steel case tula/silver bear/herters and plink away on the range. Or at someone if it ever came down to it.