The Forster 6.5mm Creedmoor NO-GO Headspace Gauge is an essential precision tool for gunsmiths to safely test rifle chamber dimensions and detect potentially excessive headspace conditions.Forster 6.5mm Creedmoor NO-GO Headspace GaugePrecision steel construction with exacting manufacturing standardsTests for excessive headspace beyond safe SAAMI specificationsEssential safety tool for professional gunsmithing operationsUsed with GO and FIELD gauges for complete chamber verificationCritical for ensuring rifle safety and accuracy this NO-GO gauge helps gunsmiths identify chambers that may have dangerous headspace conditions that could cause brass rupture and gas blowback during firing.