With an index line on the die threads, those lines are 1/36th of a full turn of the lock ring's turn that would change its position on the die 0.0714285714 inch. 1/36th of 0.0714285714" equals 0.001984127" which rounds out 3 decimal places to .002".
And there are a few reloaders that understand the die is solid, meaning if the die is raised .001" off the shell holder the top of the die increases the height of the die above the press .001". I understand life for reloaders would be much simpler if the threads for the die were 10 per inch or 20 per inch.
Forget the threads, or learn to verify your measurements.
F. Guffey









