Carbon ring

Varmint Hunter

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Long Island, New York
I've got a relatively new 7 WSM Bartlein barrel on a custom action. The barrel has about 500 rounds on it and has been cleaned regularly. It was never shot hot. The barrel is loosing accuracy fast and nothing seems to help. I took a look through the bore scope and found a jet black carbon ring at the end of the chamber.

I took a bore mop and soaked it with Bore Tech carbon remover and left it sitting against the ring for two days. I refreshed the carbon solvent several times. The ring appeared unchanged. I put a bronze brush on a short rod and tried to spin some of the carbon off thinking that it was probably soft after the soaking. Oddly enough, the black rings still looks about the same.

Any suggestions?
 
Does it look dull or shiny? It may not be a carbon ring, but carbon in the haze cracking at the end of the chamber.
I use a nylon brush a little bigger than normal, a cal larger, plenty of carb cleaner and spin it up fast in my drill. Alternating between carb cleaner and CLR.
You need a carbon solvent, brake clean, carb clean and CLR all work extremely well.
DO NOT GET ANY OF THEM ON YOUR STOCK FINISHES, BLUEING OR PLASTIC.

Cheers.
P.S.
Expect to replace your nylon brush after this, it will melt.
 
I've got a relatively new 7 WSM Bartlein barrel on a custom action. The barrel has about 500 rounds on it and has been cleaned regularly. It was never shot hot. The barrel is loosing accuracy fast and nothing seems to help. I took a look through the bore scope and found a jet black carbon ring at the end of the chamber.

I took a bore mop and soaked it with Bore Tech carbon remover and left it sitting against the ring for two days. I refreshed the carbon solvent several times. The ring appeared unchanged. I put a bronze brush on a short rod and tried to spin some of the carbon off thinking that it was probably soft after the soaking. Oddly enough, the black rings still looks about the same.

Any suggestions?
They are not very easy to remove. Some think that when they don't come out that they is a shadow along where the case ends and the throat begins. They are very real. Time, elbow grease and many products including the ones listed above plus C4 and IOSSO Paste on a patch wrapped around a brush chucked up in a cordless helps.
 
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I use a parker and hale jag with IOSSO.. you will have to keep working the throat area ... I also use CLR it works great on the throat if you let it sit awhile.. Absolutely don't get it on your stock .. It even ate my cerakote off of my brake... Love how CLR cleans but just don't get it on anything other than the inside of the barrel.. Lots of elbow grease .. Good luck!

Does it look dull or shiny? It may not be a carbon ring, but carbon in the haze cracking at the end of the chamber.
I use a nylon brush a little bigger than normal, a cal larger, plenty of carb cleaner and spin it up fast in my drill. Alternating between carb cleaner and CLR.
You need a carbon solvent, brake clean, carb clean and CLR all work extremely well.
DO NOT GET ANY OF THEM ON YOUR STOCK FINISHES, BLUEING OR PLASTIC.

Cheers.
P.S.
Expect to replace your nylon brush after this, it will melt.
 
I use a parker and hale jag with IOSSO.. you will have to keep working the throat area ... I also use CLR it works great on the throat if you let it sit awhile.. Absolutely don't get it on your stock .. It even ate my cerakote off of my brake... Love how CLR cleans but just don't get it on anything other than the inside of the barrel.. Lots of elbow grease .. Good luck!
The IOSSO bore paste always has removed the ring for me. Note, no matter how clean the barrel gets the IOSSO will turn a patch black. if you have one, check the progress with a borescope till desired results are achieved. Good luck
 
The IOSSO bore paste always has removed the ring for me. Note, no matter how clean the barrel gets the IOSSO will turn a patch black. if you have one, check the progress with a borescope till desired results are achieved. Good luck
Are you using the ISSO on a patch and spinning with a cordless drill? I tried Isso but ran the patch in line with the bore.

Butter Bean - I'd be happy to send it to you but you've got to return it after you're done. I've got a small fortune into that rifle. 😁
 
Are you using the ISSO on a patch and spinning with a cordless drill? I tried Isso but ran the patch in line with the bore.

Butter Bean - I'd be happy to send it to you but you've got to return it after you're done. I've got a small fortune into that rifle. 😁
You have me confused with Ladd-, post #7. I would never spin anything in a barrel with a drill, I've never advised doing this. I use a coated rod, nylon brush with a patch wrapped around it and IOSSO with short strokes. This was suggested for carbon ring removal by gunsmith Thomas "Speedy" Gonzales.
 
No just put it on a short rod and turn it slowly just as you engage the lands.. You can use a drill but, caution you could damage your bore if patch happened to come loose. I would say if your going to use a drill do it with your brush, Nylon preferred.. after the IOSSO use some kroil oil for a a hour to loosen it up and then hit it with the brush.
 
You can learn from this that it's best to manage on a regular basis, never letting it build up.
You can also mitigate it's formation with tight end clearance(10thou max) instead of trimming far short.
But IMO, it'll be pretty hard to demonstrate this as the cause of your accuracy falling off. It would have to be so bad as to cause potentially hazardous pressure spikes to see it on target.

Somebody needs to offer an extended end mill for this task. Like Sinclairs primer pocket uniformer,, only for chamber neck and extended 10" to a handle.
 
You can learn from this that it's best to manage on a regular basis, never letting it build up.
You can also mitigate it's formation with tight end clearance(10thou max) instead of trimming far short.
But IMO, it'll be pretty hard to demonstrate this as the cause of your accuracy falling off. It would have to be so bad as to cause potentially hazardous pressure spikes to see it on target.

Somebody needs to offer an extended end mill for this task. Like Sinclairs primer pocket uniformer,, only for chamber neck and extended 10" to a handle.
Really good idea if you could make it work.
 

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