What do you think we used out of rifled barrels before sabots were popular? Rifled barrels have been around for quite a while. They were originally designed to make foster style slugs more accurate.

You have a smooth bore that will shoot 1-2 inch groups at 100 yards? If so you should consider yourself lucky, I have never seen that before. I have seen some that shoot acceptable groups at 80 or so yards, but not what I would call good.

Paul