ar10 headspace

[fobb]

I bought a complete Ar10 upper bolt and all from Daytona Tactical. after shooting it discovered that the bolt would tear off part of the rim where the extractor was. Also it bulged the case about 1/3 up from the bottom. One time it split the case also not eject.
I purchased 308 go nogo gauges and the bolt (stripped) closes on both gauges.
Now for the stupid question---- is the headspace off and if it is what is the solution? It does it no both new Winchester brass and once fired milsurp brass.

Thank You

 

[edwardware]

. . that the bolt would tear off part of the rim where the extractor was. . . it bulged the case about 1/3 up from the bottom. . . One time it split the case also not eject. . . the bolt (stripped) closes on both (go and nogo gauges).

4 problems, somewhat related.
-Rim tearing is possibly overgassed.
-Bulging is hard to diagnose without a picture. I don't know that there's room for headspace to be so severely out of spec to visibly bulge brass. Likely a really crap chambering job.
-case splitting, in your case, is likely related to a crap chambering job
-closing on a no go is no go; stop, call the vendor. You're about to find out how their customer service is.

 

[243winxb]

Barrel & bolt should be from same manufacture/brand.

Hot loaded ammo will stick in an AR chamber & extractor will damage the rim.
Edit Add. The headspace may be different between 308 Win Vs 7.62 Nato? The Colt M16A1 headspace is different then 223 Rem.

Go Gauge: Go Gauges match the minimum chamber dimensions allowable under SAAMI specifications. In order to accept SAAMI maximum ammunition, the rifle must be able to chamber the correct go gauge.


No-Go Gauge: No-Go Gauges are sized to the maximum recommended headspace dimensions. If a rifle will chamber the no-go gauge, it may still be within specifications, or this could indicate excessive headspace. To determine if the rifle is safe to shoot, the chamber must be checked with the field gauge.


Field Gauge: Field Gauges correspond to the maximum safe headspace dimension. If a rifle will chamber a field gauge, it should be inspected and repaired by a competent gunsmith prior to use.

 

[243winxb]

First of all, the headspacing on most 7.62 NATO chambers will run 0.006 to 0.010 inch longer than their sporting rifle counterparts

https://www.shootingillustrated.com/articles/2018/8/19/308-win-vs-762-nato-whats-the-difference/