Headspacing

[Grumpyolman]

Okay so I put together a Grendel with a Faxon Arms Nitride BCG and an Odinworks 20" stainless barrel with an Anderson upper and a Strike Industries17" handguard/ barrel nut.
Everything went together smoothly. I rented Grendel go-no go gauges from Reamer Rental. When I put the go gauge in initially, the rifle failed the head space test. After my initial panic attack I disassembled the rifle, put the barrel in a padded vise, removed the ejector and extractor, and tried again. No good! I contacted Faxon and Rob over there was great, he shipped me out another bolt group that he personally checked to make sure it was in spec. It failed too. At this time I received a long awaited shipment of Starline unprimed brass in 6.5 Grendel and decided to try it with the brass. Both bolts worked! I'll be shipping Rob back a BCG.
The next question is, do I have a Too tight chamber or are the gauges off? It's a Saturday so I'll have to wait until Monday to see if I can talk to someone at Odin. I'm pretty new to ARs, this is only my 2nd build. I've been working on pistols and bolt guns for +40 years and this is the first time I've had this sort of head space issue.

[montana]

Okay so I put together a Grendel with a Faxon Arms Nitride BCG and an Odinworks 20" stainless barrel with an Anderson upper and a Strike Industries17" handguard/ barrel nut.
Everything went together smoothly. I rented Grendel go-no go gauges from Reamer Rental. When I put the go gauge in initially, the rifle failed the head space test. After my initial panic attack I disassembled the rifle, put the barrel in a padded vise, removed the ejector and extractor, and tried again. No good! I contacted Faxon and Rob over there was great, he shipped me out another bolt group that he personally checked to make sure it was in spec. It failed too. At this time I received a long awaited shipment of Starline unprimed brass in 6.5 Grendel and decided to try it with the brass. Both bolts worked! I'll be shipping Rob back a BCG.
The next question is, do I have a Too tight chamber or are the gauges off? It's a Saturday so I'll have to wait until Monday to see if I can talk to someone at Odin. I'm pretty new to ARs, this is only my 2nd build. I've been working on pistols and bolt guns for +40 years and this is the first time I've had this sort of head space issue.

If the gauge is on, then your chamber is too short.The GO gauge corresponds to the SAAMI (Sporting Arms & Ammunition Manufacturer's Institute) minimum chamber length..Short chambers are more common than over length chambers..

[AK_Reloader]

OP,
Next question would be the leade/freebore length of said chamber job.

IF,COAL is to your liking,shoot it.

IF,COAL is not to your liking, throat it.

Adj your F/L sizing die to fit brass in said chamber & do not concern your self w/ headspace gauging.

[montana]

OP,
Next question would be the leade/freebore length of said chamber job.

IF,COAL is to your liking,shoot it.

IF,COAL is not to your liking, throat it.

Adj your F/L sizing die to fit brass in said chamber & do not concern your self w/ headspace gauging.

I beg to differ, it his chamber is too short, he should send it back to have it properly chambered to SAAMI spec.. A proper throat is a whole other issue.

[AK_Reloader]

OP,
Measure the breech face counter bore depth from forward face of bolt lugs to breech face to ascertain IF you have a properly machined Type II bolt.

The dimension should be .136",any measurement a few thousandths less is going to be a NoGo w/ your go headspace gauge.

montana,
It's best to have a clue,instead of guessing.

It's not Rocket Science!!

[montana]

There is no guessing with head space gauges. Comparative gauges are not precise, .001 incremental gauges are, if a precise reading of an individual chamber is the goal. Manufacturers never use comparative gauges when chambering a barrel.. If a bolt and chamber fail the go gauge, then the chamber is too short... You are right, it is not rocket science...

[Grumpyolman]

Thanks for the advice guys, I did measure the bolt face and Rob at Faxon arms told me the bolt was out of spec. He shot me out a whole new BCG that he personally checked. The bolt still would not rotate with the extractor and ejector removed with the go gauge on a bare barrel. The new Starline brass posed no problem with either bolt. I'm waiting for Odin works to open so I can call and see what they have to say.

[AK_Reloader]

Shoot it.
Size brass accordingly.
Seat projectiles as required.

Shoot it enough & you'll be chasing the lead anyway.

[Happy2Shoot]

Is there an update yet OP?

If you fire factory ammo, or have other 6.5 Grendel rifles you will want an in-spec chamber. If you reload only, and only have this gun then it is not that big a deal. All brass you buy will be short sized, and all dies when you cam over will short size your brass.