Carbon ring?

[spudgun]

Ok guys.

Trying to determine where and if this is a carbon ring or just milling marks.

The picture below is of my Savage 12, 6.5 CM. in the picture is a brass case neck mouth and to the area circled in red is what I think is a carbon ring.

I have tried to dissolve and clean it using various methods, CLP, Hoppies Black, Bore scrubber, nylon brush, brass brush.

Does not seem to go away.

Any ideas what it is?

 

[Ralph Littlefield]

It looks to me like the shoulder where case neck ends and throat begins.

 

[jelenko]

^ Same here.
It does look like firecracking but odd that it would be there and not in the throat.

ETA. The carbon rings I've seen have a much more uniform surface.

 

[RustyInBend]

That's not a carbon right. Keep shooting and cleaning.

 

[BoydAllen]

You are seeing the reflection of the color of the neck portion of the chamber in the bevel translation to the edge of the freebore where there is some heat checking.

 

[SeabeeKen]

Looks like the end of the chamber and fire cracking in the throat. Imo

 

[williepete]

That is a baked on carbon ring
I get them all the time
good thing you have a bore scope to pick it up
if not cleaned out it will build up and can cause serious pressure issues

 

[Richard Jones]

That is a baked on carbon ring
I get them all the time
good thing you have a bore scope to pick it up
if not cleaned out it will build up and can cause serious pressure issues

No. More shadow than anything. Not a carbon ring.

 

[DShortt]

Take a bit of JB Bore Paste on a worn brush with a patch wrapped around it. Apply the paste to the end of the patch. Lightly spin it by hand making sure it's right in the case mouth/throat area. Should come out pretty easily and as mentioned above you can check your progress with the bore scope. Clean throughly before checking with the scope and use a clean patch and fresh paste every time.
It's easier than it sounds.

 

[williepete]

That looks like the inside of your chamber never have seen fire cracking in the inside of a case

 

[Chaotik]

Agree with Boyd...that does not look like a carbon ring.
Here are some of my carbon rings:

 

[DShortt]

That looks like the inside of your chamber never have seen fire cracking in the inside of a case

I think the borescope has been inserted from the muzzle if I deciphered what was posted correctly. (?) Looking at the end of the case neck and freebore/throat area.

 

[David Christian]

Ok guys.

Trying to determine where and if this is a carbon ring or just milling marks.

The picture below is of my Savage 12, 6.5 CM. in the picture is a brass case neck mouth and to the area circled in red is what I think is a carbon ring.

I have tried to dissolve and clean it using various methods, CLP, Hoppies Black, Bore scrubber, nylon brush, brass brush.

Does not seem to go away.

Any ideas what it is?

I don’t know what I see, but my carbon rings don’t look like that. I might suggest a deep, deep cleaning of JB or Iosso just to get back to a baseline.

 

[DShortt]

If we are in fact looking at the case mouth then the carbon ring won't be visible in this image because it'll be under the brass.
I think what we're looking at is a bit of fire cracking starting an the very beginning of the freebore area.
We'd need an image without brass in the chamber to see a carbon ring.

 

[Fern]

I don’t know what I see, but my carbon rings don’t look like that. I might suggest a deep, deep cleaning of JB or Iosso just to get back to a baseline.

This right here is what is used losso with a worn brush and patch around it.

 

[jelenko]

I think the borescope has been inserted from the muzzle if I deciphered what was posted correctly. (?) Looking at the end of the case neck and freebore/throat area.

So, the throat is to the left - yes? The area circled in red is at the end of the chamber - yes?

 

[RegionRat]

in the picture is a brass case neck mouth and to the area circled in red is what I think is a carbon ring.

How about a picture of the area without the case inserted.
Colors can get washed out in borescope shots, so at present it looks strange.

If this is the chamber material, I would ask what are you typically cleaning with?
If that isn't your steel, then the advice to spin a bronze brush there is what I would try next. You could add in the JB or Iosso if you have it, or at least some bore cleaner when you spin that brush there at that junction.

The reason I said it looks strange, is heat cracking is shallow but usually more spread out and not so sudden. There would normally be a larger grain boundary size to the checks and it would be a more gradual appearance. This starts up and then abruptly ends. I am wondering about a reaction rather than typical heat effects.

 

[Benchrest Braxton]

Ok guys.

Trying to determine where and if this is a carbon ring or just milling marks.

The picture below is of my Savage 12, 6.5 CM. in the picture is a brass case neck mouth and to the area circled in red is what I think is a carbon ring.

I have tried to dissolve and clean it using various methods, CLP, Hoppies Black, Bore scrubber, nylon brush, brass brush.

Does not seem to go away.

Any ideas what it is?

this picture was taken after all those cleaning methods?!?!

 

[6MMsteve]

that's fire cracking, the case is covering up the carbon ring, remove the case then scope it, might want to chk your trim length also the angle is hard to tell if the brass is close but it looks close

 

[williepete]

that's fire cracking, the case is covering up the carbon ring, remove the case then scope it, might want to chk your trim length also the angle is hard to tell if the brass is close but it looks close

I think the man with the big green tractor has hit it on the head.