Split (cracked) shoulder in barrel chamber?

[r0tt3n1]

After firing, my brass shows what appears to me anyway, is a crack in the shoulder of the chamber of my rifle. Not all the fired brass shows this, but a majority of them anyway. I have seen brass with similar markings from a cracked full length sizing die and this looks about the same to me.
The chamber of the barrel does have a very crappy cut to it overall; there are chatter marks and rings all over the neck and shoulder area. The rifling is good and it shoots very well though of course... Thanks for your help.

 

[tac284]

Is this a custom or factory barrel?

 

[r0tt3n1]

It is an aftermarket savage pre-fit barrel.

 

[tac284]

''The chamber of the barrel does have a very crappy cut to it overall; there are chatter marks and rings all over the neck and shoulder area."

This was something you observed before installing the barrel or what you can see from the loading port looking into the chamber with a flashlight? Not being able to see it first hand but based on your description I would have to say that mark is in the chamber. The mark appears to be consistent in shape which would lead me to that conclusion.

 

[SBLH10]

Looks like a brass bristol mark from the brass cleaning brush.

Chet

 

[tac284]

These are the marks in question correct?

 

[r0tt3n1]

''The chamber of the barrel does have a very crappy cut to it overall; there are chatter marks and rings all over the neck and shoulder area."

This was something you observed before installing the barrel or what you can see from the loading port looking into the chamber with a flashlight? Not being able to see it first hand but based on your description I would have to say that mark is in the chamber. The mark appears to be consistent in shape which would lead me to that conclusion.

(edit to clarify) Yes, from the get go before I even installed the barrel. With a Lyman bore scope I saw the chattering and ring marks in the chamber area. But I do not see anything that could cause this particular marking. Then within the last 70ish rounds or so I started seeing this particular mark appearing.

These are the marks in question correct?

View attachment 1253638

Yes, and the 2 tone coloring that seems to be caused by it.

 

[B Nettesheim]

That’s a mark left from the reamer during chambering
It was still cutting when they pulled it out

 

[r0tt3n1]

Looks like a brass bristol mark from the brass cleaning brush.

Chet

I do not use brass brushes. I prefer to use felt pellets.

 

[tac284]

That’s a mark left from the reamer during chambering
It was still cutting when they pulled it out

I second this...

 

[gme]

no dwell at the last reamer pass left a interrupted cut, depending on how deep it may be able to polish it out

 

[Ggmac]

Have you been using a new die ? Say one to bump shoulder

 

[tobnpr]

Agree with the above, only way I can see that occurring.
Usually machining artifacts would be circular for obvious reasons, this is a rather shitty Savage OEM, brandy-new:

 

[NorCalMikie]

The rifling is good and it shoots very well though of course???

Don't fix it if it ain't broke!!

 

[NorCalMikie]

With a Lyman bore scope I saw the chattering and ring marks in the chamber area.

That was your FIRST problem!! Bore scope= bad Ju Ju.
Second problem is trying to fix something that you perceive to be a problem.
See previous post # 14.

 

[r0tt3n1]

Agree with the above, only way I can see that occurring.
Usually machining artifacts would be circular for obvious reasons, this is a rather shitty Savage OEM, brandy-new:

This is an aftermarket barrel, and it does have those circular thingies as well...

 

[r0tt3n1]

Thanks for all the replies. A local smith agrees with y'all that it is just machining marks. He said he could polish it, or if it is not causing any extraction issues (it is not) just live with it.. I am a cheapskate, I will live with it.

 

[MNbogboy]

Production barrels don't see the reamer & chip cleaning that we do when doing them for ourselves. Personally I would run the reamer in a few thousandths and clean that shoulder area up.