I bet I probably could, eventually, get the AB to group somewhat. I tried proven powders at proven charges in varying seating depths out to 1.20" jump. I've used imr4350 up to max book, in increments of .020" jump, but did not see groups tighten or appear to group. Just randomness.
In contrast to SGK, for example, I'd see MOA groups (100 yars) at .020" jump across 4-5 charge weights, each charge .3g apart...basically those 4-5 charges all impacted at the same 1" group on the target.
That performance compared to the AB makes me think that the ABs just don't shoot well, or like you said might require more tweaking to make em work.
Not sure if the SGK would be strong enough to pass through bears at 2-300 yards, given an ideal broadside shot.
Thanks for all the input.