I've had great success for tight groups from my little Sako 19" carbine with 3031. I'm using the same loading now as back in 1971.
70-grain Hornadys for varmints, and 85-grain Sierra HPBTs for deer. 1/2 MOA with the Hornadys; at most 3/4 MOA with the Sierras.
Max at 40.0 and 37.5 grains, respectively, which is what my father had been using from the beginning days of the .243's existence.
While I've not really kept count, I know there have been over a thousand rounds shot, and the last time at the bench I put three behind a dime at 100 yards.
You're from BATFE? Come right in! I use all your fine products!