You can shoot rifled slugs with your smooth barrel, but not the sabot slugs (well you can, but it would be like shooting a 1700's smoothbore musket). Just put in you Imp or modified tube. You may also be able to get a rifled choke tube to shoot the sabot style slugs. If you want it to be a really good slug gun, buy their rifled barrel with the cantilevered scope mount. We have popped a few island deer with my wife's. I'd rather shoot a 20 ga slug than a 12 any day.