Concentricity Gauge:
A concentricity gauge is a tool used to identify and measure bullet runout.
The Accuracy One Concentricity Gauge allows you to Measure the runout of ammunition and ammunition components.
The Concentricity Gauge measures the internal and external neck runout of your cartridge case as well as seated bullet runout. It can also measure the runout of the ogive, bearing surface and boat-tail of individual bullets and can even measure your primer pocket runout.