Forster Products 223 Remington GO, NO-GO, & Field Headspace Gauge Set, SAAMI Dimensioned, Rimless, Hardened Steel, Precision Ground

Precision-manufactured steel headspace gauges Made in USA

• 223 REMINGTON: Used to check headspace of 223 Remington and 6mm x 45
• RIMLESS CARTRIDGE HEADSPACE: The proper use of Headspace Gages is the most reliable way to test rifle chamber length. Headspace in a rimless cartridge is the distance between the bolt face and a datum line, determined by SAAMI, where the front of the cartridge rests on its shoulder when the bolt is closed.
• GO: Corresponds to the minimum chamber dimensions. If a rifle closes on a GO gage, the chamber will accept ammunition that is made to SAAMI maximum specifications. The GO gage is essential for checking a newly-reamed chamber in order to ensure a tight, accurate, and safe chamber that will accept SAAMI maximum ammo.
• NO-GO: Corresponds to the maximum headspace we recommend for gunsmiths’ chambering new bolt-action rifles. This is not a SAAMI-maximum measurement. If a rifle closes on a NO-GO Gauge, it may still be within SAAMI specifications, or it may have excessive headspace. To determine if there is excessive headspace, the chamber should then be checked with a FIELD Gauge. The NO-GO Gauge is a valuable tool for gunsmiths’ reaming new chambers, in order to ensure tight and accurate headspace
• FIELD: FIELD Gauges are slightly shorter than the SAAMI maximum in order to give a small safety margin. If a rifle closes on a FIELD Gauge, its chamber is dangerously close to, or longer than, SAAMI-specified maximum chamber size. If chamber headspace is excessive, the gun should be taken out of service until it has been inspected and repaired by a competent gunsmith.