Sabot type slugs don't do well from smooth bore shotgun barrels even with rifled choke tubes but the older foster type slugs do well with a rifled choke tube. If you just gotta use the newer sabots for sure use a rifed choke but don't expect wonders from it.
For buck shot you really gotta try them and see. I'd not go tighter than Modified but even IC might be better you really just have to shoot your load in your barrel with different choke tubes to know.
