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 Go Gage only. Both a Go Gage and a No Go Gage are required to properly headspace a barrel.
These Go Gages represent the lower limit of SAAMI specifications for proper headspace dimensions. If the action closes with this gage is inserted, then the firearm is within acceptable minimum headspace dimensions.







