Brass is an alloy of copper and zinc of which cartridge cases are usually made. This term is often applied to empty cartridge cases. Typical cartridge brass has a copper/zinc ratio of 70/30.

Our Concentricity Gauge measures the internal and external neck runout of your brass 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.