The 223 is NOT ideal for deer, nor is ANY 22 cal. But they will work, if you know your limits. If you use it then you have to realize that you WILL be forced to pass up some shots that would be doable w/ a larger caliber. So if your patient and willing to pass on shots, then you can use the 223. Down the line a ways after you've used it for awhile evaluate how well it works for YOU, if you lose deer w/ it quit, if you are finding nearly all the deer you shoot then continue.