The most accurate sabot I have found in my Hawkens with that 45 LRH barrel is the 200 gr SST with the tan sabot. It shoots1" groups at 100 yards. with 90 grains of T7 or select and a Remington cap. i still have a lot of expermenting to do with it as far as conicals though.
It wouldn't shoot powerbelts at all except for the 300 gr Platinum. The 225 and 195 regular powerbelts never would come together, even with only 80 gr. The platinumsd grouped at about 2" or a little over