The RCBS Case Master Concentricity Gaging Tool is a tool designed to help reloaders create the most accurate ammunition possible. This tool easily measures neck concentricity, uniformity, thickness and bullet run-out to ensure that all reloading equipment is setup to product the most accurate rounds possible. This tool can also be used to detect case head separation before any symptoms are apparent on the outside of the case.

Accuracy: .001″
Features: Fully-adjustable V-blocks to securely position the case for an accurate measure, compact base for convenience but still steady enough for the tasks at hand