One good video, there are others, showing how the Hornady Headspace Gauge set works with your calipers. Very good tool and works with most all rifle calibers. Measure the shoulders on factory rounds, measure a case fired in your rifle, and adjust your sizing die to push shoulders back for a semi-auto at 3-4 thousandths and a bolt rifle up to 2 thousandths.
https://www.youtube.com/watch?v=P-UrMTyJ1_E