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Old 12-26-2012, 11:18 AM
M14 M14 is offline
Join Date: Jul 2011
Location: south mississippi
Posts: 874

Originally Posted by Sailormilan2 View Post
I just got a set of Forster gauges from Brownells, and I ran into a similar issue as you regarding the 7.62 NO GO. I ordered a 308 FIELD, a 7.62 NATO NO GO, and a 7.62 NATO FIELD. What I got was:
7.62 NATO........ 1.6455 MAX

Gauge #2 should have been marked 7.62 NATO NO GO. It has the right part number(100-010-715), but the label on the case says 243-308 NO GO GAUGE. But the gauge itself does not say what type of gauge it is, just the caliber and length.
Number two should have been marked SAAMI or WINCHESTER maximium. No go is either 1.634, or the older ones are 1.636 I already have two Forster 308 gauges and they are marked:

243-308...NO GO....1.134"

Both of these should be the proper markings for the 243-308, so I don't understand how the 7.62 NATO No GO could be labeled 243-308 1.640.
Because they are confused, and confusing everyone else. I can assure you, the military is not cutting all their chambers for 7.62mm, longer by .0025 From what I understand, the 1.640 is actually longer than 7.62 NATO NO GO, but shorter than 7.62 NATO REBUILD MAXIMUM GAUGE. I also think that the NATO FIELD gauge should be marked as FIELD, not "MAX".
I have written to Forster and am waiting a reply.
The NATO gauge of 1.6455 is marked properly, it is max.
The field is actually 1.6375 for NATO, not 1.638.
the 1.638 gauge marked 243-308 field is to let you know that you are .002 away from max for SAAMI standards, and should think about getting ready to buy another barrel soon. It is a rebuild number or max rebuild. If it reaches this number, supposedly, it is time to rebuild. But I have never seen an M14, commercial or military, open up the headspace even one thousandths more. So you have quite a while until one that size ever does anything or sets back.
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