Search is your friend here - lots of prior discussion on this. The short of it is that a rifled slug is made to be shot out of a smooth bore. There are many who do successfully shoot rifled slugs out of rifled barrels. The downside is that the rifling in the barrel will tend to get fouled with lead and require more frequent cleaning.
On the other side, you can safely shoot a saboted slug out of a smooth barrel, but you'll likely get poor accuracy and you wallet will be seriously pained as the sabot slugs cost WAY more than rifled slugs.