Provides a quick and easy way to sort cases by neck wall thickness and uniformity. This tool allows you to accurately measure the neck wall thickness of the cartridge case and determine its uniformity. Two mandrel sizes are supplied to allow measurement of all cases from .17cal to .338 cal including cases with small (.060) flash holes. For your convenience the mounting base allows direct attachment to your reloading bench, or use the Redding double "C" clamp (#30520). Pilot stops are required for each caliber. Two pilot stops are supplied with the tool - .22cal and .30 cal.