Also, one thing you might notice, as you start getting close the case may actually grow in length ie instead of bumping back, you'll see a longer measurement, then once you make contact with the shoulder, it will start getting shorter. For a bolt gun, I'd look for a bump back of .001-.002" and for a semi-auto, the rule of thumb seems to be .003"-.005".
Keep in mind during setup that 1 full turn of the die equates to about .071" in depth into the press (14 threads per inch on the die) so you're going to be making VERY small adjustments to your die depth. I highly recommend that you use a locking die ring of some sort, like Hornady or Forster rings, even RCBS and Redding lock rings have a set screw to lock them in place. Use it and it will make setup the next time a bit easier. The only ones I've used that don't have some sort of locking mechanism is Dillon. Not sure about lee or lyman, never used them.