Help: Is this a carbon ring?

[Muddyboots]

Just a curiosity question: Have there been lead cast bullets shot in this rifle? Otherwise agree start with really good scrubbing back down to steel so you have a known starting point for loads going forward.

 

[mrjashu]

Just a curiosity question: Have there been lead cast bullets shot in this rifle? Otherwise agree start with really good scrubbing back down to steel so you have a known starting point for loads going forward.

Just the opposite actually. He only shot Barnes all copper bullets to my knowledge.

 

[Truc]

I took a snap shot of your pics, this is definitely a carbon ring and a pretty bad one

 

[mrjashu]

I just wanted to give an update on this.
I gave the barrel a deep cleaning over several days with four different solvents. I now have nicknamed that rifle "the copper mine" because of a the gobs of copper that came out of it. The copper was followed by gobs of carbon.
I went out and shot it, ran a quick ladder charge test and it pressured up normally! Hurray!
Incidently I couldn't make much of a dent in the band of carbon that sits in front of the case mouth but I was able to remove all the carbon in the throat area. I chambered a case and ran the bore scope down the muzzle end and verified that indeed the case ends right at the edge of that black band. In any case the rifle is shooting good again.
Thanks for all the suggestions!

 

[25WSM]

Good job. That carbon on the end of the neck will give you accuracy issues. It's best to keep it from starting. Put a patch soaked with carbon remover in that spot and let it soak. Then take a brush one caliber bigger than your bore and twist it on that spot. It will come out. Once it's gone it's easy to keep it gone with the twisting brush.
I'm glad you got all the copper out too. I've had so many rifles brought to me that quit shooting good. When I ask them how they clean it I know right away if it's fouled out. A deep clean and the rifles shoot good again.
Shep

 

[johnnyk]

These two pics illustrate to me, at least, how, why and where a carbon ring develops in my barrel. This rifle is my 6.5-284 Norma, stock Savage w/Lothar Walther pre-fit.
The first photo is with a cartridge case in the chamber with the bolt locked down. The case was prepped fully; meaning it has been trimmed as all the reloading manuals suggest; 2.160" (max OAL of 2.170" - .010"). This particular case is actually a bit shy of 2.160" and is at 2.1595". This encourages me to let my brass "grow" longer than 2.170" as it would actually fit the chamber better lengthwise. I can only surmise that this would allow the carbon ring to develop a bit further forward, like not in the chamber portion.
The second photo is oriented 180* from the first with chamber being on top. This was taken after one cleaning with bore scrubber for the barrel and does nothing, that I can see, for the carbon ring in ones chamber.
It took "several" sessions with nylon brushes (.24-.28"), patches, JB Bore Cleaning paste, carbon killer and SeaFoam. These (carbon ring) are not impossible to remove but sure are a PITA.
I don't have a pic of it completely clean but it is now. I have gone through all my brass, but have not trimmed. Once I learn what the MAX OAL of my brass can be then I'll go from there.
Hope this helps.

 

[26Reload]

The first definitely shows your carbon ring...but the second looks extremely clean...the little area that seems discolored looks like the final edge of the chamber cut.....
Before and after of one of mine....