I'm not a pellet shooter, but generally speaking, pellets are more target-consistent because their "per pellet" weight and volume is again generally more exact.

The more exact you are -- the better you shoot muzzleloaders. Weigh your bullets then put them into table groups to be more exact... seat you bullet with exact pressure every time..... squeeze the trigger & exhale & hold your breath with the same finger/lung pressure.... etc... etc.