AR-Series Headspace Gauge 5.56 NATO MIN and 5.56 NATO NOGO set

The 5.56 GO gauge is used to measure the minimum allowable chamber headspace. If the bolt does not close on a GO gauge, it is considered unsafe headspace. The NOGO gauge is used to measure the Maximum recommended chamber headspace. If the bolt closes on a NOGO gauge, it is out of the recommended new to good condition range. It should then be checked with a 5.56 Field (MAX) Gauge to determine when the headspace is unsafe and should be taken out of service for rebuild. This gauge set ships in the USA only, No export or APO.