Forster 6.5 Grendel SAAMI Dimensioned Field Length Rimless Headspace Gauge

Every gunsmith understands that using a headspace gage is the most reliable way to measure the length of a rifle chamber. "Headspace" refers to the distance between the face of the breech and the base of the cartridge when the action is closed. Excessive headspace is not only dangerous but can also impair accuracy. For example, unsupported brass fired in a rifle with excessive headspace may rupture, causing gas to blow rearward with explosive force, similar to rocket exhaust. Because your safety