Forster 6mm Remington/.244 Remington SAAMI Dimensioned No-Go Length Rimless Headspace Gauge

Proper utilization of a headspace gauge is the most reliable method for assessing the length of a rifle chamber. "headspace" refers to the distance between the breech face and the base of the cartridge when the action is closed. Excessive headspace can pose safety risks and negatively affect accuracy. For example, unsupported brass fired in a rifle action with excessive headspace may rupture, causing gas to escape rearward in a manner similar to rocket exhaust. If a rifle closes on a NOGO gauge,