After a lot of trail and error I found what my Mountaineer likes the best. It was a very hot day near 90. Let barrel cool for 10-15 minutes in between shots. Distance was 100yds, loading 110g. Blackhorn, Crush Rib Harvester (black), 250g. Barnes T-EZ Flatbase. I had a good group with the just the sabot and bullet, but I also tried wrapping the bullet in very thin paper ( the kind that you might see in a gift bag pushed in to cover up the gift) By using this combination I was able to tighten up the bullet/sabot fit a bit and the results were excellent.