It does well in 600Jr and Spolars. Not so well in MEC progressives. The Spolar has a small vibrator which shakes the powder for extremely consistent load where the 600 Jr rattles back and forth so many times before powder drop that it also is very consistent. The progressive MEC are so smooth and only operate once for every powder drop that they can be plus or minus a bit with 800X. Never loaded800X on a PW when I was running them but suspect it would be like a MEC progressive and a bit plus or minus.
