Brought to market by the ammunition experts at Hornady Mfg., the Lock-N-Load Concentricity Tool ensures consistency and performance from production and handloaded ammunition. Concentricity, or bullet runout, is the relative straightness of the bullet in relation to the cartridge case. When a seated bullet exceeds acceptable runout—typically 0.002"-0.003" for optimal performance—the bullet’s initial jump from cartridge case to rifling lands begins off axis. The result is decreased accuracy and “fliers.” The Concentricity Tool is not just a gauge, but a tool to rectify those runout errors, whether in custom handloads or factory-loaded ammunition. Setup time is minimal, but a few practice runs are necessary. Once assembled, place a cartridge into the tool and rotate against the dial indicator. For adjusting runout, simply notate the lowest and highest measurements. With the thumb screw on the sliding cradle, tighten against the bullet onto the high-side measurement. The applied force will shift concentricity toward its low-side measurement. Check for runout again and adjust accordingly until desired concentricity is reached. Included are three bullet spindles to accommodate a variety of bullet profiles. Price: $150. Contact: Hornady Mfg., (800) 338-3220; hornady.com.