Forster Products Headspace Gauge .308 Win (Go 1.630)

Headspace Gauge Features Because your safety is on the line Forster Headspace Gages are made with painstaking care and exacting manufacturing standards to ensure accurate testing of your rifle's chamber. If a rifle closes on a GO gage the rifle chamber will accept any ammunition that is made within S.A.A.M.I. (industry standard) specifications. If a rifle closes on a NO GO gage the rifle chamber might have excessive headspace. Most gunsmiths chamber a rifle's headspace between the GO and NO