I got a muzzleloader about 8 years ago. I have shot nothing but sabots out of mine. I have shot the buffalo bullet sabot, and then swithced to the precision rifle original sabot. Those have shot really well out of my muzzleloader. I used the 300 gr bullets. Then this year I switched to try the Thompson center XTP Mag, 240 gr. This is the same bullet as a Hornady .45 cal pistol bullet. But in the end buying them already together was pretty close to the same price. Anyhow those shoot really well for me also. And this last Thurs. I harvested a two point deer at about 100 yards with that. It dropped in its tracks, and went straight throught the animal? There are a lot of good bullets out there. But I can recommend the precision or the Thompson center XTP Mag (Hornady Pistol bullets).
Good Luck
Buck