I'm sure there is an advantage for someone who spends much of his time flying in helicopters, but other than that I don't see the very short .45/70 being of much of an advantage. On the down side both muzzle blast and recoil increase without any ballistic gain, although the loss in velocity would be at worse minimal. But the sight radius is shorter, so hitting at distance becomes more challenging. Would a 16" barreled rifle allow you to respond quicker if a bear stuck his head in your tent? Maybe, but if I was the bear I wouldn't my life to depend on the difference. A more important question might be how the abbreviated barrel might effect the handling characteristics of the rifle. If the rifle is very butt heavy, getting on target quickly, and getting the sights to settle down on target might prove difficult.