"Does sub moa at 100 yards translate to sub moa past 600 yard?" - Shoot it and see.
I dabbled in the dark arts of OCW, Ladder test and seating depth. I became lost in an obsession to make a small group, smaller and smaller. I lost friends, quit talking to family and became consumed by that last .001 I could get.
All that stuff can lead to good trigger time at a set distance, but it pays more to get out and shoot. Find an MOA load and go do some shooting. Try to find a spot to stretch out and see what you got. Go try a competition, I guarantee you'll learn a lot there.
rfurman24 - we need to go shoot sometime!