rwj
Gold $$ Contributor
Too bad none of the commercial run out gauges hold cases headspacing on their shoulder align like they are when fired. Any case out of round condition at case body resting points can alter run out readings.
One could use, or have made, a case gauge that emulates the chamber. It could be made such that the bullet, and a portion of the neck, is exposed for runout measurements when placed on the TIR gauge.