I watched the videos posted by Sheldon N about finds the length to your lands, but seating a bullet and putting it deeper and deeper by the .001 until the bolt handle closes freely. Or measuring brass by sizing it down and until you reach the same result. Then how to you measure your results so they can be repeatable. Do you need micrometer dies? It sounds like the Hornady gauges that go on calipers are not accurate? So if they aren't accurate how to you know how to set up your dies next time, if you can establish the proper length of the brass but van't use the caliper? I have a heap of federal brass I want to begin to reload. How should I proceed. I'm shooting .308 out of a DTA SRS.