I had the opportunity to speak to an actual hunter last week and he told me that not only would you not likely get the chance to use a second bullet in your clip, let alone a third...
"'Cause if you miss him with the first shot, that buck is gone. Forget it, he's just gone."
...but if you're inspected by a game warden while out hunting, there are restrictions on exactly how many rounds you can have in a clip in your gun. And the limit isn't somewhere close to the 30-round capacity of an AR-15, it's more like five. FIVE.
And like my hunting acquaintance pointed out, it's really only the first one that you're likely to get to use.
"And if you're caught with that many rounds in the gun, the warden'll just take your gun. Confiscate it, slap with you a fine, and you deserve it. Those aren't armored-up deer out there, you don't need that many rounds in your gun."
I asked him about having an AR-15 for "home defense."
"Not useful. Rounds go right through walls, so if you miss you might hit your own family on the other side of the wall. If you're worried about home defense, a shotgun full of birdshot is better. Won't go through the walls. Of course, if I was really worried about home defense, I'd move."
And there you have it.