Mine will shoot a number of loads under a minute of angle. It take the right sabot for a particular bullet for instance the long black harvester [300gr+] is what it takes along with 110gr of Blackhorn to shoot the 250 gr Gold Dot well, the Short Black Harvester does real well with the 250 gr Shock Wave, the FTX and the bonded Shock Wave, The blue MMP shoots the 200 gr Lehigh and the 200gr Shock Wave with a 140 gr load of BH The long black harvester and the 300gr Gold Dot do very well with 115 gr of BH. I have never seen a gun that shot every thing real well you have to refine what any gun likes and with a sabot muzzle loader I personally start with getting the right sabot by loading a 100gr load of BH and a Winchester primer and use that for a constant while I try all the different sabots that fit the barrel reasonable well when I find the thickness of sabot the gun likes the I try all the sabots that are available with the different bullets I want to use.
As a for instance on how that works I use my Triumph which likes the MMP HPH 24 which is the same thickness as the Short Black Harvester and the long black Harvester which shoot so well in my Endeavor Encore. Due to the variation in barrel dimensions the first thing is finding out what fits well enough to have a good chance of working. If they are so hard to load you want to beat on them or they go down so easy that you don't need both hands then they probably wont shoot good.