I do not have any experience with Power belts, but I can attest to the quality and accuracy of the " Dead Center" bullet by Precision Rifle Bullet.
I currently use 3 pyrodex pellets and a 220 gr. Dead center and Winchester 209 primers. This load consistently groups 1 m.o.a. <1 ragged hole> @ 100 yds all day!
Never thought I' d see a ML do this!