Necessary when finish chambering a barrel or when checking the chamber of a used gun to be sure the headspace dimensions are within safe limits. This is a No Go Gage only, and both a Go Gage and a No Go Gage are required to properly headspace a barrel.
These No Go Gages represent the upper limit of SAAMI specifications for proper headspace dimensions. If the action closes with this gage inserted, then the firearm may not be within acceptable maximum headspace dimensions and should be examined further by a knowledgeable gunsmith.







