Well, I've shot men with an M-4 (basically a shortened M-16 firing the same 5.56 ammo) and I've seen it take a couple of rounds to put a guy down. For my money the .223 is a little light for deer. Not saying it won't kill one deader than charity at the DEM convention but there are much better rounds available. Therefore it isn't "perfect" despite what another member has claimed. There is a world of difference between killing a deer standing still perfectly broadside and killing one on the move quartering away, no matter what the distance is. A perfect cartridge or caliber is one that can get to the vitals no matter what the shot angle is and the .223 with expanding ammo simply can't do that. FMJs will do it but not soft points designed for hunting.

Just my 2 cents worth. Feel free to disagree if you wish too.