Bob, did you check RTZ after?
Also, next time I would suggest dialing it back down to zero, then up again 10 MOA, and try another group while the atmospherics are the same. You can check it at 600 next time at the range but it'll almost certainly print the group somewhere else due to different wind, temperature, etc.
And finally, if you shot a 100-yard Tall Target test I'd think you were even cooler.
Lot of fun to be had playing with TT's..... grin. But seriously, there is a wealth of data there on the scope's function, minus most of the atmospheric influences that muddy things at 600 yards.
