Quote Originally Posted by gotcha
Measure your HD SP gauge w/ your comparator. Take a couple readings 'til you're comfortable w/ the measurement. Next, measure at least three pieces of your fireformed brass the same way (make sure you have removed the primers to get a correct reading) If your HD SP is correct the two measurements should be identical. The fired case may be a half thou. smaller due to the case contracting slightly after firing.
We are good to go. I measured the HD SP gauge I get 1.640.(still under SAAMI) cases measure the same.
Thanks for everyones help. I now understand Headspace.