The L.E Wilson Case Gauge is a tool designed to check overall length (min/max) to indicate the need for trimming and, when used with the L.E Wilson Case Gauge Depth Micrometer, this Case Gauge checks the datum-to-head length to assure correct headspace and to prevent excessive re-sizing of the cartridge case.
This one-piece gauge will check overall length to indicate the need for trimming, datum-to-head length to assure correct headspace and to prevent over sizing. A calibre-specific gauge is available for most popular rimless cases. The Cartridge Case Gage was designed with safety in mind and was invented by founder Sam (L.E.) Wilson in 1935 after a fellow shooter approached him for help in solving a case-separation issue. The gauge allows you to measure just how much you are sizing back the shoulder on your cases.
This is best done by following the steps below.
Measure a case in the "as fired" condition, using the L.E Wilson Case Gauge Depth Micrometer. Note the headspace measurement.
Resize the case on the current die setting.
Then place the case back in the gauge to see just how much the shoulder is being bumped back. As before, this can be measured by using the Case Gauge Depth Micrometer.
Finally, adjust the sizing die accordingly to achieve the desired shoulder set back.
After sizing your cases, there is a good chance the brass will lengthen. The gauge will also check min/max case length and will point out the need for case trimming. This is an essential tool for every reloader.
Note: This Case Gauge does not measure body diameters. It is intended to be used with fired cases to determine a basis for full-length sizing and trimming.