Nice groups
I had a similar drop in POI when I ran the Biz Mags through my baby. Again my Zero was with AAF's (only difference was its .22)
Also I notice that your BizMag group was (bulk of) to the left as was mine
A heavier pellet retains nore energy down range than a lighter pellet, BUT as I am going to tell you, most others will agree here.
If you can put a pellet in the kill zone, the quarry is going to die quickly and it's not down to the weight, cal or retained energy of the pellet its where you put it
Phantom