Polishing the chamber may have solved my issues

[c3k]

Folks,

I have a homebuilt 6.5G. I used an Alexander Arms barrel (20", fluted) and their bolt. I coupled that up with an Adams Arms micro-adjustable piston kit and various other stuff.

I had bolt overruns, stovepipes, and failures to extract.

I -think- I had two separate issues.

At first, I focused on the gas and buffer. Thinking an H2 and low gas setting had solved my timing (bolt overruns) issue, I then tried to focus on the FTEs. The brass (I've never fired any lacquered ammo) would jam, hard, in the chamber, with the bolt trying to load the next round. That isn't optimal.

I had to mortar (not too hard) the rifle to get the bolt to extract the stuck round. This would happen every 5th round or so. Examining the extractor, it seems fine, as does the extractor spring.

Well...I could not find a 6.5G chamber brush, so I used a 5.56 one. I put it on a cleaning rod, wrapped it in cotton patches, put in my drill, and after loading it with Flitz polish, I went to town on the chamber. I made a mess. After cleaning it up, that chamber and the lugs were GLEAMING!

I have not had a failure to extract since I did that.

I also went back to a standard carbine buffer and have not had any feeding issues since.

So, I think the problems were: rough chamber which caused FTEs, and an improper bolt weight causing timing issues.

FWIW.

Ken

[kmon]

Not the first that I have heard of or seen hat a rough chamber caused issues. helped one guy with what looked like over pressure issues with near starting loads in a 7mm Nosler. When I saw a fired case there were a few light ring marks on the case body. He took the barrel back to the smith that chambered it and after a few minutes with a hone no more issues and that was in a boltaction

[kmon]

Glad you got it figured out

[pacificpt]

Nice when you are able to work through a problem and get it solved. How is the accuracy?

[c3k]

Accuracy...

At this point, all I've fired through it is Hornady 123gr ELD Match (Hornady Black). I've got a bipod and a Vortex Viper PST II 3-15x scope. Shooting at 100 yards I had dreams of single ragged holes.

My latest outing was a little rushed. I fired a single 24-round magazine at 2-3 rounds per second (10 second total time) and had all of the rounds impacte in a space covered by hand at 100 yards. This was more about function. The next shots were slower, another 58, firing at a dueling tree and letting my friend and his son have some trigger time. (Hyperfire trigger...yeah, very nice.) So, no data on accuracy.

Now that I =think= I've got it working, I'll buy some other ammo and see what it likes. N

This if my first 6.5G and I'm very impressed with the power and ease of firing this round presents. I'll definitely be adding more 6.5G's to the collection.

[FLshooter]

I was getting a scratch on the bottleneck of my new Hornady cases.It was intermittent.Only did it on around 50 cases.A local gun store owner that builds AR platforms told me that if the problem persisted ,I could get a fire formed case,screw it to a cleaning rod,through the primer hole and use some lapping compound or metal polish.
Now,since it only did it on 50 pieces,we had figured that it was the brass.Maybe the annealing process?I never tried polishing my Grendel chamber,since the problem solved its self.
But,I am going to keep that idea in my mind.Sounds like it could come in handy in the future.

[HickLife]

I might need to do this to a 458 socom I have. I have the same issue with FTE and having to slam the stock on the ground several times to get it out. It's about as frequent as yours was but when it's stuck it's STUCK. It would probably be a great gun if I could make it through more than 5 rounds before having to mortar it.

[c3k]

I was getting a scratch on the bottleneck of my new Hornady cases.It was intermittent.Only did it on around 50 cases.A local gun store owner that builds AR platforms told me that if the problem persisted ,I could get a fire formed case,screw it to a cleaning rod,through the primer hole and use some lapping compound or metal polish.
Now,since it only did it on 50 pieces,we had figured that it was the brass.Maybe the annealing process?I never tried polishing my Grendel chamber,since the problem solved its self.
But,I am going to keep that idea in my mind.Sounds like it could come in handy in the future.

I considered this (the used brass with compound), but I thought the brush would be softer as a first step.