Headspace issue on 458 Socom

[theaccountant]

How should I approach resolving this issue? Just finished a 458 build with a tromix barrel, Wilson combat stripped upper, and a toolcraft 458 bolt / bolt carrier group. Purchased go and no go gauges from pacific tool and guage and the bolt closes on the no go guage. How should I proceed in seeing what the issue is? Should I just go purchase the tromix bolt? Any help is much appreciated.

 

[243winxb]

Purchase the tromix bolt or try a field gauge
.

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]

If the Tromix bolt and barrel dont produce the correct headspace, contact them for a replacement .


Pacific Tool and Gauge offers three lengths of headspace gauges per rifle caliber. In order from the shortest to longest, they are: GO, NO-GO, and FIELD:

1. GO: Corresponds to the minimum chamber dimensions. If a rifle closes on a GO gauge, the chamber will accept ammunition that is made to SAAMI’s maximum specifications. The GO gauge is essential for checking a newly-reamed chamber in order to ensure a tight, accurate and safe chamber that will accept SAAMI maximum ammo. Although the GO gauge is necessary for a gunsmith or armorer, it usually has fewer applications for the collector or surplus firearms purchaser.
2. NO-GO: Corresponds to the maximum headspace Forster recommends 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 checking a newly-reamed chamber in order to ensure a tight and accurate chamber.
3. FIELD: Corresponds to the longest safe headspace. If a rifle closes on a FIELD gauge, its chamber is dangerously close to, or longer than, SAAMI’s 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. FIELD gauges are slightly shorter than the SAAMI maximum in order to give a small safety margin.

 

[243winxb]

https://www.ar15.com/forums/ar-15/Headspacing_458_socom_/121-698866/

There are two different chamber reamers used both of which are ".458 Socom".

 

[XTR]

How much is it off? If it's not a ton treat it like any wildcat (which it actually is because there is no SAMMI spec) seat some long enough to jam them and shoot it then size your brass according to your chamber.

I've also had 223 brass from a once fired batch that I got that was over sized by about .010. Still goes bang when you pull the trigger.

A bigger issue would be if it was short and you could not chamber factory ammo, that has been known to happen too with the 458.

 

[nicholst55]

How should I approach resolving this issue? Just finished a 458 build with a tromix barrel, Wilson combat stripped upper, and a toolcraft 458 bolt / bolt carrier group. Purchased go and no go gauges from pacific tool and guage and the bolt closes on the no go guage. How should I proceed in seeing what the issue is? Should I just go purchase the tromix bolt? Any help is much appreciated.

Can you tell us your method of checking headspace? I'm not suggesting that you don't know how, but rather I'm honestly interested.