I use the Hornady Bullet Comparator and the Modified cases, it's easy and very accurate. I also use a Frankford arsenal digital caliper, which makes reading measurements faster,( I believe)along with trhe Comparator.
Also jwrowland, what is the reason for .02 jump? I mean how did you come to this conclusion, or is it even a conclusion or just a starting point? Myself, I try .003-.005 at a time, in increments, testing three rounds until I find "The One" and I have several different ones that I came up with while trying various different bullets, and bullet weights in my 7mm Rem Mag.... just saying...