This thread has been here a few times before, but it`s still interesting. Like i`ve said, the .223 will work, and using the right bullet i`ve taken 200 pound does with know problems at 300 yards. But these are under perfect conditions, from sandbags and broadside shots. I use a .223 is because the landowners don`t like noise, and the wildlife officer says that it`s either a .223 or buckshot, otherwise i would use a .308, which IMO is the best round for killing deer cleanly, and still having something left to eat. But then again rumluver, that`s not a bad choice either.