I use Remington Slugger 12 (rifled) slugs in my smooth bore and that gun with that load is a 125yd gun easy. I site in at 100yds and have touching groups. I hunt in WI and like most states that restrict rifle use shots on game are mostly within 100yds. I think with the modern design of firearms, ammo, and accessories any 12ga or 20ga is more than enough to take a white tail. Remember a great hunter never brags about how long a shot was but how close it was. Let the dog hunt the birds, ... you hunt the dog.