I had the same problem when I first started " fooling" around with my Black Diamond last year. The " solution" that I came up with was to toss the sabots, lower the powder charge to 100 grains, and load the 245 grain Aerotip Powerbelts.
All of that, coupled with a minor scope adjustment or two brought the groupings to under 3" at 100 yards. I' m dead on at 50 yds.... just what the doctor ordered.