With the RCBC precision mic, the head space of this case measured about -0.005" (way over-sized) while my unsized once fired cases measure an average of -0.001" so would using these two measurements be a good method to say that i would need a Redding competition shell holder that is 0.002" to allow me to cam the press over and have the head space measurement im looking for of -0.003" ? (0.002" shorter than a fired case)
I think that should do. Try it then post the measurements. Use fired cases to test with.