Brownells AR-15/M16 Colt 5.56 NATO Maximum Headspace Field Gauge 1.4736"

The Brownells AR-15/M16 Colt 5.56 NATO Maximum Headspace Field Gauge is a precision gunsmithing tool used to verify chamber headspace on AR-15 and M16 pattern rifles. Measuring 1.4736 inches, this field gauge identifies chambers that are at or beyond maximum headspace tolerances, helping ensure safe and reliable function. Designed specifically for Colt-spec 5.56x45mm NATO chambers. An essential tool for gunsmiths and armorers performing chamber inspections and barrel installations.