Question for the knowledgeable:
I have a Sinclair Concentricity guage & am told the dial reading (rotation on the case body) should be halved to determine actual run-out. Is that correct?.....or not?
I'm also told the Hornady guage (because its rotation is from case head & bullet point) gives an actual run-out reading, so is different from the Sinclair. Is that correct...or not?
I'm trying to understand how if the dial pin is measuring from the outside of neck/bullet in both cases, why one can be different from the other.