Forster Products 8mm x 57 Mauser, GO Headspace Gauge,SAAMI Dimensioned, Rimless, Hardened Steel, Precision Ground
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. This gauge ships only in the USA, No export or APO.