You can shoot rifled slugs out of rifled barrels, it will not hurt them. And some of them are pretty darn accurate. I can get between 1-2 inch groups at 100 yards with some of them. This is what was used in fully rifled barrels until sabots became popular. However it does make a mess and is not very fun to clean the barrel. It is no different than shooting lead bullets out of a rifle/handgun or conicals out of a Muzzle Loader.

Another down side is the ballistics are not that hot compared to sabots, especially the newer designs. And they are only accurate for a few shots in some guns before you need to clean the barrel. The up side is they cost between 2 and 7 bucks a box compared to 10-15 bucks for some of the the sabot rounds.

Paul