Hornady Lock-N-Load Thickness Gauge 17-22 CAL RIM

Sorting ammo by rim thickness will provide ammo with similar ignition qualities for improved accuracy.This proven technique is used by competitive shooters and varmint hunters.The rimfire gauge attaches to your caliper and includes bushings for use with most (not compatible with 17 WSM) .17 and .22 caliber rimfire ammo.