I'm new to reloading for accuracy instead of cost. I bought a Hornady OAL guage and made an insert with .350" bore to measure the location of the case shoulder. My plan was to measure some fired cases and adjust the decapping/resizing die until it pushed the shoulder back .002".
However, on both my rifles (sako 75 30-06 and sako 85 7mm rem mag) even when i screw the die all the way down all the way to the shell holder (at top of ram stroke) the location of the shoulder doesn't change.
I measured some new winchester 7RM brass and it averaged 2.103"+/- .003 and my fired cases measure 2.120"+/- .001 so i know the cases are expanding i can repeatably measure differences in headspace.
is it possible that the chambers in both guns are short enough that the die doesn't touch the fired cases even when it is all the way down? am i misunderstanding something? photo of my die set and measurement setup: