AR-15 headspace issue criterion barrel

[bradworley]

I have a new criterion barrel chambered in 223 Wylde that failed the go gauge.
I removed the extractor and the ejector from the bolt but cannot get the go gauge to turn?
Any ideas???
Microbest bolt
Barrel is not installed on the upper yet
Forster gauges

 

[jb0311]

Email criterion. Their CS has always been great in my experience.

 

[bradworley]

Email criterion. Their CS has always been great in my experience.

I guess I'm going to have to. Just tried the gauges on my Ruger 556. Go gauge passes, no go failed.
I also tried the bolt that was in my Ruger on the criterion barrel. It failed the go gauge as well.
Damn!

 

[msgriff]

Make sure the chamber is scrubbed clean.

 

[Constructor]

All it takes to fail is .001" but .001 may mean/do nothing. Try some loaded factory ammo in the chamber, if it fits shoot it. Most factory ammo is well below the size of the go gauge.

 

[msgriff]

All it takes to fail is .001" but .001 may mean/do nothing. Try some loaded factory ammo in the chamber, if it fits shoot it. Most factory ammo is well below the size of the go gauge.

True, but for .223 Rem, the minimum SAAMI chamber length is 1.4636" ("GO"). SAAMI maximum cartridge length for .223 Rem commercial ammo is 1.4666" (-0.0070").

 

[Hardholder439]

You probably have a tight "match chamber." I had a similar issue with a Krieger barrel in 6.5 CM and a JP bolt. I was testing them as you were extractor and ejector removed, barrel uninstalled. Go gauge would not go. Desperate, I started inserting live factory ammo to see if anything would chamber. Using an RCBS precision Mic, I was able to determine the Go gauge was .002 over SAAMI minimum. Any factory cases that were SAAMI minimum or below would chamber easily. Obviously YMMV. That was my experience. Don't give up because the go gauge is lying to you.

 

[Molon]

I have a new criterion barrel chambered in 223 Wylde that failed the go gauge.
I removed the extractor and the ejector from the bolt but cannot get the go gauge to turn?
Any ideas???
Microbest bolt
Barrel is not installed on the upper yet
Forster gauges

What's the length of the go-gauge that you used? Did you try any other go-gauges?

For reference, Criterion uses a 1.4646" go-gauge when they sell a barrel with a "head-spaced bolt." If your go-gauge is truly a 1.4636" gauge, there could be a problem with the chamber. Just because a factory loaded round will chamber in a barrel, doesn't mean that the chamber has the correct headspace. Most factory ammunition is sized well below the SAAMI minimum. An undersized chamber can lead to increased chamber pressures.

...

 

[Millennium200]

I keep a few bolts for occasions like this.

 

[bradworley]

What's the length of the go-gauge that you used? Did you try any other go-gauges?

For reference, Criterion uses a 1.4646" go-gauge when they sell a barrel with a "head-spaced bolt." If your go-gauge is truly a 1.4636" gauge, there could be a problem with the chamber. Just because a factory loaded round will chamber in a barrel, doesn't mean that the chamber has the correct headspace. Most factory ammunition is sized well below the SAAMI minimum. An undersized chamber can lead to increased chamber pressures.

...

I'll have to mic the go gauge when I get home later today but it is labeled 1.4636
Also, I tried a couple of factory rounds and they all passed.

 

[bradworley]

I keep a few bolts for occasions like this.

I tried 2 different bolt and they both failed the go gauge.
Both bolts did however work with multiple factory rds

 

[Constructor]

True, but for .223 Rem, the minimum SAAMI chamber length is 1.4636" ("GO"). SAAMI maximum cartridge length for .223 Rem commercial ammo is 1.4666" (-0.0070").

I'll have to mic the go gauge when I get home later today but it is labeled 1.4636
Also, I tried a couple of factory rounds and they all passed.

I'd shoot it.
I had to pressure test the 6.8 barrels we made. The proof ammo I had Hornady make came in at 94,000 psi. Never once came close to breaking a bolt or blowing a barrel, the fired cases look pretty bad though.
If the ammo fits in the chamber but chamber is a touch on the small size there is no danger. If the chamber is over the field gauge size then you may get flattened or primers that have backed out.

 

[bradworley]

Holly shi... 94k psi! I've never actually measured pressure (or even seen the equipment required to do it) but that's nearly 50% more pressure than recommend
I'm going to call criterion tomorrow and go from there. But I probably will end up shooting it unless criterion says otherwise