Out of all the deer I've shot and several bear, I've only needed a second shot on 2 deer (one of those was a finishing shot on a downed one). But I don't see any reason that a semi shouldn't be allowed. Yeah you will get the idiot that believes faster follow up shots will overcome his shooting ability. But I would really like to take a deer with my AR-10. It wouldn't be a regular thing though because that rifle is heavy compared to my Browning Micro Hunter or even my Marlin guide gun.