Re: bullet comparators
remember this, they are comparators designed to compare the length of your loaded rounds and as you know if you get different readings, your bullet seating depth will be at fault.
Theoreticly, do the same with the one which is 004" bigger and again you will find that if you have different reading your bullet seating depth will be at fault.
You could say it is like measuring a given diameter with 2 micrometers, 1 new and 1 old, worn and out of calibration, you are going to get 2 differing readings.
I use the Stoney Point version that clamps onto the blade of your Vernier calipre and has interchangeable calibre specific bushings.
"I mean't to shoot the pike but the duc got in the way"