First- what do you mean by "smoth [sic] bore slugs"?
If you mean the slugs that you can currently buy, then yes.
You can also shoot slugs out of a full choke, but most "slug" barrels are cylinder bore.
If you're shooting sabot-encased slugs, you'll likely get better accuracy out of a rifled barrel.
Try several brands to see what works best with your gun.