I've had the opposite experience as the others. The Harvester short black sabots haven't worked as well as the crushed ribbed sabots for me. A friend and I switched to them, and in one gun the short black sabots loaded fine and were plenty accurate. However, in the other gun we just had a heck of a time loading it. We had to beat the ram rod down the bore as it was too hard to do it by hand after a shot.

So I decided to order some of the crushed rib sabots and tried in both. In the one where the bore was so tight, the crushed rib sabots loaded perfectly and shot accurately.

In the other gun the crushed ribbed sabots loaded easier than the short black ones too and to my surprise it shot just as well as it had with the shot black sabots.

This just goes to show every gun is different so some may like the crushed rib sabots and others may like the short black ones.