There's a lot of talk on the web about this. From what I've read, the arguments tend to be about 65% against using .223 to take deer, with about 35% for. Yes, there are more powerful rounds for this job, but there's a lot of anecdotal evidence that a well-placed shot, using modern 70 gr. high powered ammo, can drop a deer with one round. Not to mention, its legal in many states, so it can't be that unrealistic. Many hunters swear by the .223's killing power. Federal Premium even makes a round especially for deer and such mid-sized game: http://www.federalpremium.com/products/details/rifle.aspx?id=6 Wanted to see what people here thought. EDIT: Note my typo- I meant ".223" in the title.