To OP, perhaps the issue is your press? I too have the Classic Cast Turret press, and I have found that I get very uncertain results on bottleneck cases when trying to arrive at uniform shoulder setback. Perhaps a change to a Rock Chucker or the like will assist you some.
Too PMA make a lock ring that will help you in setting your dies for proper shoulder bump.
Die Lock Ring PMA
Lastly, unless you anneal your cases each time, the best I have achieved in terms of consistent shoulder bump is +/- .001 from my target setting. There are inconsistencies in brass springback otherwise as the brass work hardens. Lube film thickness will also affect your results. I have found the Lee toothpaste lube when applied with an atomizer, and diluted about 6 to 1 with ISO alcohol gives the most consistent lube film, without sticking cases. Also, since some gets in the case neck, the expander ball doesn't drag the neck out of concentricity on many cases. Some do get out of line.
HTH.