The Forster 7.62x51mm NATO 1.633-Inch Go Gauge (brand part no. HG308-1.6330-SP) is a precision steel headspace gauge confirming a 7.62x51mm NATO chamber has been cut deep enough for the bolt to close properly on a correctly dimensioned case. Forster Products machines it to a fixed 1.633-inch length representing the minimum acceptable headspace for this military-spec chambering, which runs slightly different from commercial .308 Winchester tolerances. The bolt should close freely on this gauge in a properly finished chamber, and it’s used alongside a no-go or match gauge as part of a complete headspace check. Stock it with the rest of our gunsmithing tools and gunsmith supplies for military-pattern rifle builds.

Key Specifications

• 7.62x51mm NATO Chambering Ground to the military-spec minimum headspace dimension, distinct from commercial .308 Winchester tolerances.
• Go Gauge Type Confirms the chamber is cut deep enough for normal bolt closure on a correctly dimensioned case.
• 1.633-Inch Gauge Length A fixed, precision-ground reference length for a repeatable check.
• Steel Construction Hardened steel that retains its critical dimension through repeated use.

Frequently Asked Questions

Is 7.62x51mm NATO headspace the same as .308 Winchester? They’re dimensionally close but not identical; military 7.62x51mm chambers are cut with slightly more clearance than commercial .308 Winchester specifications.

When would a builder use this gauge instead of a standard .308 gauge? Specifically when verifying a chamber intended to run to military 7.62x51mm NATO specification rather than tighter commercial .308 dimensions.

Buy the 7.62x51mm NATO 1.633-inch Go Gauge, Forster

Military-spec chambers deserve a gauge built to that same spec. Order this go gauge from our Lubbock, Texas gun shop for fast, insured shipping to your bench.