I think it's Harvester crush ribs sabot. I have a CVA kodiac .50 cal, I had the same problem loading my bullets with the sabots that came with it.I read some threads here and bought a pack of crush ribs and it did make the loading easier. I haven't shot my rifle yet but I did load the bullet in the rifle and it was pretty easy compare to the ones that came with the pack. I think the crush ribs shouldmake your loadings easier.