The new Hornady Ammunition Concentricity Gauge can be used by both reloaders and factory ammunition shooters to make run-out a thing of the past. This is the first tool on the market that both identifies and eliminates bullet run-out. Once a loaded round is inserted into the Lock-N-Load Ammo Concentricity Tool, the dial indicator is used to adjust the cartridge run-out to zero. The Ammunition Concentricity Gauge can also be used to true-up factory ammunition. Weight: 3.65 lbs.