Good point rdstrain49. I actually tried to be careful with my changes. I have not changed the bullet, other than to try a powerbelt (did not like it). Prior to going to loose powder, I used the 777 pellets (100gr), and only dabbled between the ribbed black and smooth black sabot. I liked the ribbed the most. Next time out I switched to BH209 powder (and the appropriate breech plug), and shot the favorite bullet/sabot combo with good results at 80 grains. Groups tightened and it mattered not if the barrel was unfired or fired, hot or cold. Next was increasing the load slightly in order to see even better grouping at 100 yards.
I am going to do one final major change. I ordered some red ribbed sabots. Will the larger sabot fit into my barrel okay, and will it improve my results? If nothing really changes, then back to the black ribbed sabot. Once that is resolved, I will have the bullet, sabot and type of powder taken out of the equation. The final piece of the puzzle will be, how many grains of powder (so far 85 gr by volume is the leader).
Do you think I am on the right track? Pete