Weird markings on fired brass

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10-25-2012, 09:46 PM
cast1

Weird markings on fired brass

Just finished my first build. 110 action, Shilen select match in 260 remington. Headspaced with Forster gauges. Bolt hangs about a third of the way through its arc on the no go gauge. My first five shots show concentric marks on the shoulder as shown below. It almost looks like there was a burr or nick on the reamer when it was made. The shoulder looks kind of funny too, almost distorted. Is this anything to be worried over?

http://farm9.staticflickr.com/8192/8...9587d01d85.jpg
2012-10-25_21-26-21_734 by bsshep1, on Flickr
10-25-2012, 10:22 PM
seanhagerty

You might try cleaning the chamber with steel wool on a qtip thats chucked into a drill. just go at it a bit and then see what happens
10-26-2012, 04:34 AM
LabRat2k3

Yeah there is something not right with the shoulder on that fired brass. I would suggest doing a casting of that chamber and check to see if it is in spec.
10-26-2012, 06:44 AM
FUBAR

Better use another headspace gauge, looks like it's "bumping" the brass for you!
10-26-2012, 09:32 AM
barthowes

+1 on the bumping brass. Looks to me like your headspace is on the small side and your "crushing" your cases. If there was a burr you would see it.
10-26-2012, 01:51 PM
Gmac5

Was it a full charge or just a lite fireform ? If it was a lite load it may not have expanded the case enough. If it was a full or near normal load i think a chamber cast and a call to who ever chambered it is in order.
Gary
10-26-2012, 01:52 PM
Gmac5

Forgot to ask is it 7.62 x51 military brass or 260 brass?
10-26-2012, 03:53 PM
FUBAR

I have a old design 280AI, and if I use Nosler 280AI brass they have .014 more headspace, and I have to bump the shoulder back...if I bump too much they look sorta like your picture.

However the prior question about the brass is applicable...
10-26-2012, 04:33 PM
cast1

Federal factory loads just to get on the paper and break the barrel in. I had backed off the go gauge just a hair before I snugged the nut down, thinking it might tighten a little when I torqued it down. I took it all apart and re-did the barrel install just that slightest bit tighter. I was more worried the first time about too much headspace vs too little. This is a pre fit from NSS.
10-26-2012, 08:10 PM
Gmac5

Take a fired case and measure id , it may be lrger than you think
10-26-2012, 10:45 PM
MrMajestic

Could the chamber have been damaged by leaving the go-gage in the chamber when snugging the barrel nut? Just thinking out loud.
10-26-2012, 11:57 PM
stangfish

Take a picture of the chamber if possible and the picture of the brass and send it to Shillen.
10-27-2012, 10:47 AM
jonbearman

Was this a pre-fit or did a gunsmith chamber it? If it is a pre-fit,send it back as it looks like the reamer was severly worn to me.
10-27-2012, 07:51 PM
ellobo

Tightening the nut will back off the barrel a small amount. I don't remember how much. I think Sharpshooter can confirm this if he chimes in.

El Lobo
10-27-2012, 11:30 PM
cast1

Re-did everything with the tighter headspacing and tried it again. Same result, only farther up on the case shoulder. I took a couple more pics:

http://farm9.staticflickr.com/8333/8...8bc426e4df.jpg
Default title upload by motoblur by bsshep1, on Flickr

http://farm9.staticflickr.com/8333/8...8f7c0d25ba.jpg
Default title upload by motoblur by bsshep1, on Flickr

You can see that there is basically a bunch of fine scratches on the shoulder and a positive ring around its diameter. It looks like a chip got stuck on the tooling and gouged out a defect. You can see the waviness in the photos. I thought I was buying the best that Shilen had to offer. I will contact them to see if they will make it right, but in my mind, something like that should never leave the shop.
10-27-2012, 11:32 PM
cast1

It was a pre-fit.
10-28-2012, 12:00 AM
cast1

Quote:

Originally Posted by MrMajestic

Could the chamber have been damaged by leaving the go-gage in the chamber when snugging the barrel nut? Just thinking out loud.

Did not leave the go gauge in when tightening the nut.
10-28-2012, 10:58 AM
BillPa

Quote:

Originally Posted by ellobo

Tightening the nut will back off the barrel a small amount. I don't remember how much.

El Lobo

On the average .001"-.002" depending when the threads are tensioned, although I had one tighten up. Never quite figured that one out. :confused:

Whats bug'n me, in the picture the shoulder isn't fully formed and it appears to be a quite a bit of blow back on the neck,shoulder and the body. The bright ring on the shoulder looks more like it was wiped off than a mark on the brass. It has every indication of a light charge and/or excessive headspace-head clearance.

http://farm9.staticflickr.com/8192/8...9587d01d85.jpg

It almost looks like when I'm working up the charge using COW and Unique to form improved brass and the starting charge is too low, rounded shoulders and blow back, the brass not expanding enough to seal the chamber.

At this point I'd do two things. First remove the barrel, clean the chamber them drop the GO gauge in and measure the amount of protrusion and second, make a chamber cast. The protrusion would verify the chamber length and the cast a visual verification of the shoulder.

Bill
10-28-2012, 11:00 PM
cast1

Well I think I figured it out. Took the barrel off and shined a flashlight down in the chamber. The shoulder is very rough and is a mirror image of what I am seeing in my brass. Don't know how often this happens, but I figure if it's going to, it will happen to me. Just glad I didn't get a face full of hot gas. I will be contacting Shilen and Northland tomorrow to see how they will handle it.

http://farm9.staticflickr.com/8331/8...da03f69d0d.jpg
Default title upload by motoblur by bsshep1, on Flickr
10-28-2012, 11:06 PM
cast1

Why are my posts having to wait for administrator approval? I have posted three other pictures in two posts and I get told they won't be visible until they are approved by an administrator. Am I on probation or something?

The problem is with the chambering of the barrel. I took it off tonight and sure enough it looks very rough down in there. There is a picture of it in one of the posts awaiting admin approval. Maybe it will show up. We'll see how it gets handled either by northland or Shilen.
10-29-2012, 11:23 AM
jonbearman

I would seriously send it back and have them check it out or make a chamber cast to confirm if the angles are clean and sharp.Your case looks rounded in the wrong areas.
10-29-2012, 02:03 PM
mnbogboy2

A couple of years ago I had a Shilen (from midway) with a similar mark only more pronounced raised ridge all the way around the slope of the shoulder....Actually was a flaw from the chambering process...They promptly replaced it....Yours looks similar...
10-29-2012, 05:00 PM
cast1

Quote:

Originally Posted by mnbogboy2

A couple of years ago I had a Shilen (from midway) with a similar mark only more pronounced raised ridge all the way around the slope of the shoulder....Actually was a flaw from the chambering process...They promptly replaced it....Yours looks similar...

http://farm9.staticflickr.com/8331/8...03f69d0d_b.jpg
Default title upload by motoblur by bsshep1, on Flickr
10-29-2012, 05:01 PM
cast1

Quote:

Originally Posted by mnbogboy2

A couple of years ago I had a Shilen (from midway) with a similar mark only more pronounced raised ridge all the way around the slope of the shoulder....Actually was a flaw from the chambering process...They promptly replaced it....Yours looks similar...

http://farm9.staticflickr.com/8333/8...8bc426e4df.jpg
Default title upload by motoblur by bsshep1, on Flickr
10-29-2012, 05:23 PM
Gmac5

Looks like the roughing reamer went too far or bad finish reamer
10-29-2012, 09:03 PM
MrMajestic

Dang C1, that looks terrible! I'd think the Manufacturer would want that back. JMHO
10-30-2012, 12:48 AM
cast1

Quote:

Originally Posted by MrMajestic

Dang C1, that looks terrible! I'd think the Manufacturer would want that back. JMHO

I guess stuff happens. I never thought to take a look into the chamber before I installed and shot it. I was too busy looking at the rifling. I have been instructed to send the barrel back to Shilen. I am glad to give them a chance to make it right, which I'm sure they will. You will hear about it, one way or the other.
10-30-2012, 03:46 PM
northlander

I just got off the phone with Shilen advising them of your photo's. The photo of the chamber is excellent. It does show the shoulder area and should help Shilen to better understand what they need to look into.

Jim Briggs
NSS
10-31-2012, 08:46 PM
MrMajestic

Jim's on it, good for you C1! Jim is a great guy to have on your side.
11-12-2012, 12:12 AM
cast1

Thanks Jim,

Talked with Jennifer who inspected my barrel. They offered to replace it. I'll follow up when I get it back.
11-14-2012, 10:57 PM
cast1

Well, I got a nice surprise. I got a UPS shipping notification from Shilen Rifles saying that my barrel is scheduled for delivery tomorrow! That's less than a two week turnaround for a brand new barrel. Not bad, not bad. I'm quite sure I will be happy with this one. Thanks Jim and Jennifer at Shilen for helping your customer. You're only buying yourself more business.

Brian
11-16-2012, 03:15 PM
BeatCJ

Did they say what had caused the problem?
12-29-2012, 09:15 PM
acemisser

Quote:

Originally Posted by BeatCJ

Did they say what had caused the problem?

yeah man what was the results on this barrel..Is it corrected or not we want to know about it...thanks
12-31-2012, 06:46 PM
acemisser

I would like to see this poster tell us what he found out the problem was with his rifle...