Blackheart right on 22 cf kill deer but are not the best deer round in any way or form.I have killed only 3 deer with 223 and all where very dead but the last one I shot ran 60 to 80 yards and there was no blood I found the deer after a 15 min search.The bullet did not exit on the heart shot deer no bones hit just some front leg muscle.The bullet 55gr rem reload I know a premium bullet will make the 22 cf behave bigger but good god man there is so many other better rounds out there.I have found that real serious rifleman use the 22cf not slob hunters so as everybody that knows anything about anything knows its where you put the bullet.