If you get a rifled barrel and put a scope on it, plus use ammo like the Win. Partition Gold, I would buy the 20 Ga. It is so accurate you can place your shot as well as you can with a rifle, and these new slugs make a shotgun more like a pretty heavily loaded .45/70 instead of a shotgun. This includes the 20 Ga.!! It is NOT as powerful as the same kind of load in a 12 Ga., but it' s PLENTY for anything less than a Kodiak bear!!