Like every magnum T/C inline with a 1-28" twist, your rifle likes almost any kind of sabot/bullet between 180 & 375 grains. If you have one that sprays a sabot/bullet too much, simply change the plastic sabot manufacturer (Harvester?MMP) by purchasing one of their 50-packs. The optimum bullet weight (in my opinion) is 300 grains. The optimum powder volume varies. There are a suprising number of T/Cs that shoot 3-pellet loads well -- but starting at 80 grains & working yourself upwards until groups spread is still the best method if you intend on sticking with only one style bullet.

With conicals, the short lightweight ones (245-275 grains) shot well with around 100 grains FF while the real heavies (370-490 grains) performed best between 110-120 grains FF for us last month hunting.