They shoot well out of my Mossberg 500 with a fully rifled barrel. Pretty much same POI as the Winchester sabot slugs.
However, I have some concerns on their performance. My son shot a wounded whitetail that my buddy had already hit. He was at about 20 yards. When we skinned the deer later I found the slug. It had stopped on a rib, though it did break it. The slugs look like an inverted ashtray or bowl with the opening to the rear. The plastic wad fits in there. The front end is big and flat.
Now I don't know if there was something odd about this particular shot but that's terrible penetration. With sabots out of the same gun I've never found the slug still in the deer and have more than once broken both shoulders.