Setting up resizing die frustration....

Here is the deal, I had my die all set up and working well, but on Friday I received my sinclair bump gauges (that I am getting a lot more consistent readings with by the way) either way I figured I would reset up my dies and only try to bump the shoulder back .003 (before I was .004-.005) I figured with the new guage I would be able to get it really fined tuned where as before it got a lot of variance so I went for a little more bump back so everything would feed. Either way i measured 20 cases got my fired measurement. Then I set up the die as recommended and checked 5 cases, I was getting only .002 so I moved the die a little and re tightened everything down I then ran the 5 cases through and checked them, everything seemed good to go. So I went and resized all of my cases, then I grabbed 10 from the end of the resizing process and they were measuring longer then the amount I started with... so I went to reset up the die again but of course the lock ring moves the LNL part of the setup, and I can't just move it a little to know where it should be becuase the whole die moves when I am trying to undo the locking nut or anything else.... is there a trick to getting it right or is this just part of the fun and frustration of reloading?

Thanks for the help.....