The G-3 Rimfire Thickness Gauge is a very simple and accurate tool designed for sorting rimfire cartridges by rim thickness. Rimfire cartridges headspace off the rim of the case, thus different thicknesses create different cartridge headspace situations. The G-3 tool not only allows you to sort your ammunition by rim thickness, it enables you to measure the actual thickness of the rim. One tool works for .22 LR, .22 WMR, .17 HMR and .17 HM2. Includes safety neck lanyard.
The G-3 tool is designed to use with either dial or digital calipers. Calipers are sold separately.
Sinclair, Issue:4B, Page:124