Not sure what is causing this??

[Kickin-Ewoks]

This is on a brand new build. The round fires but the case will not extract from the chamber. I rand down the list of faulty buffer spring, BCG, gas block, gas tube and so on.

Then I installed a an old BCG with a week extractor, upon firing the BCG went back fully and started to chamber a new round; however, the empty case was still in the chamber. I had to use a cleaning rod to remove the empty case. I fired another round and repeated this failure.

After examining three 5 spent cases I noticed a spiral grove around the cases just below the neck. I am puzzled! Is this a problem with the barrel or chamber? The barrel maker is closed until after the holidays so I can't contact them right now. The barrel maker is reputable and I do not want insinuate anything; therefore, I will not name the manufacture at this time. The barrel is a 1:7 5.56 NATO, 16”, cold hammer forged, chrome lined, MPI, and HPT.
Any ideas?
http://i1140.photobucket.com/albums/n568/jjames7725/JonPhone226.jpg

[ra2bach]

can you get a look at the chamber? this is interesting because my first thought was there might be a burr on the inside of the chamber and the spiral marks were because of the rotation of the bolt in lockup.

but I think that spiral mark goes around further than the amount of rotation of the bolt. I'm interested to hear the eventual cause...

[polymorpheous]

Sounds like your chamber is rough.
Contact the manufacturer.

[Iraqgunz]

Unfortunately no one here has harnessed the powers of mind reading so WD can't help you if you tell us more.

1. What ammo are you shooting?

2. Who makes the barrel?

If you can't tell us then wait till they open back up.

[Kickin-Ewoks]

First I would like to make a correction; I was mistaken, the barrel is not CHF. The manufacturer is Green Mountain. I always use DD barrels for my builds, and this rifle started out with a DD.

I got this barrel for $140 but I am going to put the DD back on it. I just wanted to try something different and I read good reviews about GM.

Anyhow, I am using Lake City xm193 and xm855. I looked inside the chamber and I can see the groves. I'll probably just ask for a refund from GM and no longer deviate from my routine. I'll try to get some pictures of the chamber for you guys.

[Iraqgunz]

Gotcha. It sounds to me like the chamber could be tight and or out of spec and that is causing drag which is preventing normal extraction.



First I would like to make a correction; I was mistaken, the barrel is not CHF. The manufacturer is Green Mountain. I always use DD barrels for my builds, and this rifle started out with a DD.

I got this barrel for $140 but I am going to put the DD back on it. I just wanted to try something different and I read good reviews about GM.

Anyhow, I am using Lake City xm193 and xm855. I looked inside the chamber and I can see the groves. I'll probably just ask for a refund from GM and no longer deviate from my routine. I'll try to get some pictures of the chamber for you guys.

[The_Hammer_Man]

First bad customer review of a GM barrel I've heard of so far. Been using their barrels for almost 3 yrs now.

Their CS has always been first rate in my experience.

[Kickin-Ewoks]

First bad customer review of a GM barrel I've heard of so far. Been using their barrels for almost 3 yrs now.

Their CS has always been first rate in my experience.

I'm not bad mouthing GM, I was just curious to know if anyone on here had seen this problem before. I have read good things about GM but that doesn't change the fact that I have a problematic barrel from GM. Take it how you will; personally, I will be asking for a refund and going back to Daniel Defense.

[Kickin-Ewoks]

I removed the barrel and took a picture for anyone interested. One of my good friends works at Brux Barrels so I'm going to run it down there today and have him look at it.

Thanks for the input guys.
http://i1140.photobucket.com/albums/n568/jjames7725/JonPhone1030.jpg

[TomMcC]

No revelation here, but your chamber is cut improperly. From the groove in the fired case and the chamber picture you have a raised ring of steel close to the shoulder. If it's not chromed line you could have it re-reamed, or have GM replace it.

[Kickin-Ewoks]

Yes it is chrome lined. I actually contacted customer service at GM today, the guy I talked to was courteous and seemed genuinely concerned with this issue. He told me to mail it back and they would inspect the chamber and replace it, if need be. Being that its chrome lined I'm sure they will just replace it.

No refund on my money but that’s ok if they send me a quality barrel. These things happen with almost every company; demand goes up and QC suffers, it’s not such a horrible issue if they take care of their mistake.

Again; I am not trying to bad mouth GM, I just haven’t experienced this problem so I wanted to hear what some of the senior members had to say about this issue.
Thanks again.

[fixit69]

Send it back. GM has a decent product from what I have used of my friends. And yes it looks like chamber. I'm sure they make good on it. Keep us updated.

[Dustin Cantrell]

Let us know how it works out. I have a GM barrel but haven't shot enough rounds through it to really test it out. No problems yet, though.

[Kickin-Ewoks]

Let us know how it works out. I have a GM barrel but haven't shot enough rounds through it to really test it out. No problems yet, though.

I shipped it out this afternoon, I'll keep you guys updated. Just from talking to GM customer service I am confident they will fix the problem.

[cz7]

''ringed chamber'' caused by main reasons - forcing the tooling or dull tools or lack of lubrication/coolant etc

[FJ540MN]

I got a Springfield 1911 with the same thing... It happens.

Springfield choked and burned me on the gun, fortunately the shop I bought it from stepped up and took care of me.

GM is doing you right. Kudo's to them.

[Kickin-Ewoks]

After weeks of calling GM they finally told me they never received my barrel, so I gave them the tracking number which showed it had been sighted for by their shipping manager. They apologized for the hassle and sent me a new barrel.

I put a few mags through it today and it functions. I know a few mags really doesn't tell me much about the barrel quality, but it does function.