1. Sabot slugs in a rifled barrel are very accurate.
2. Shooting sabot slugs through a smooth bore is a waste of money. They will "work" but accuracy suffers and there is no reason to spend the extra money for sabot slugs if you are going to shoot them through a smooth bore. Besides, if they are not flying straight and nose-first, they will not expand as designed.
3. Different shotguns "like" different loads. Just like rifles and pistols. You must try different loads to find what your gun "likes".
4. Shooting a non-sabot rifled slug through a rifled barrel can cause them to shoot into very nice groups.
5. When we got home and cleaned the rifled barrel, the five non-sabot, rifled slugs had not really deposited any lead that we could notice. The barrel cleaned-up sparkling clean very easily.
6. It's fun to shoot stuff.
Thanks to Vern for the loan of the shotgun and for help hauling all the equipment.