Hasn't Ken Waters or someone else tested this against lab pressure or strain gauge results? I don't ignore the Voodoo but as others have posted I trust the chronograph and published data more than anything else. To many variables like brass hardness and chamber dimensions at work for me to trust case head or web measurements, combined with my lack of ability to consistently measure beyond three or four decimal points.
Almost 18 years ago I ran a test using a very good micrometer on three different cartridges, then had the same handloads pressure-tested in a piezo laboratory. On one cartridge the technique was very close, the second turned out to be way underloaded, and the third turned out to be way overloaded.
The the handloads' velocities turned out to be a much better indicator.
Wrote this all up in an article for Handloader. I haven't bothered to mike a case since then.
