Headspace Gauge 223 GO
The GO gauge is used to measure the minimum allowable, safe chamber headspace.If the bolt does not close on a GO gauge, it is considered unsafe.Must have for rechamber jobs to set the new headspace or to verify the correct headspace of a new barrel and bolt combination.   These days, I see a lot more AR style new barrel and bolt combos fail the GO gauge than anything.  Failing the GO gauge indicates the headspace is too tight, which increases chamber pressure and failure to go all the way in battery.  This leads to pierced and popped primers that will damage the firing pin tip and cause slam fires.  It also can cause hard extraction and damage to case heads.  The GO gauge should be used to test any new barrel and bolt combination or when swapping in a new or used bolt.   This gauge is for use in all .223 and 5.56 NATO chambers as the .223 GO and 5.56 Min gauge are the same. This gauge ships only in the USA, No export or APO/FPO.