If 75 yards was my max, I wouldn't think twice about the shotgun. You'll get plenty of accuracy, and have a dual use gun if want. A 30-06 at short range just punches a hole and usually ends up with little expansion. If you must go rifle, I'd use one of the slower moving calibers, 30-30 44mag etc. I shot a deer at 52 yards with my 270 on friday and it looked like it was shot with an arrow with a field point. entry and exit wounds were small, and little blood trail. Just my experience though. If you want a total slug gun, the old browning A-bolts are at the top of the heap if you can find one.