carbon ring

[PGS]

Hi all, can anyone tell me where a carbon ring usually forms in a barrel
regards to all

 

[tome]

this happened to me on a 22 winchester 52d target rifle right in front of the throat. boars head & krols w/ a brush took it out. strange thing is it shot the same with or without

 

[fdshuster]

As seen with my Hawkeye borescope, at the front of the chamber, where the case mouth sits. The longer the gap between the end of the case and the end of the chamber the worse the problem will become. The main reason I want my chamber lengths to be no longer than .010" longer than max case length. For those who are over-trimming their cases, following the typical loading manual recommendation of .010" shorter than max case length, they are creating a problem area that need not exist. Not unlike firing a large number of 22 Shorts in a 22 Long Rifle chamber. JB bore paste with a snug fitting bronze brush will remove it with little effort.

 

[PGS]

Thanks for your help and taking the trouble to reply guys

with regards

 

[fdshuster]

gunny: I should have added, another form of carbon will usually build up starting about 6" in front of the chamber and continue for about another 6". From there to the muzzle, I've rarely seen carbon in any of my barrels. Some of my barrels will accumulate carbon on the top of the lands, the grooves will be carbon free, and other barrels will have it on the lands and also streaked in the grooves. Probably more "answer" than you were looking for, but I'm just relating what I see (and know) with my borescope. With it I'm able to keep it under control, as I also am able to do for copper.

 

[PGS]

fdshuster, my gunsmith has a borescope I will get a look down the barrel at weekend. When I clean the barrel it shoots ok for about 4 or 5 rounds then pressure builds up and the velocity increases its a tight neck chamber in 6.5x284.
When the barrel was new I gave it 2thou clearence with no issues. After about 500ish rounds down I started to get these problems.I gave some of the brass more clearence 4thou 2thou each side and still have these problems, this is why I think I may have a carbon ring. ps The cases do not have donuts.

with regards

 

[wapiti25]

I have seen pressure build in a 6.5-06 when the throat started to get rough from the fire cracking. The rough surface can give carbon or copper a place to hang on to. The bore scope should give you an answer. Take it to him dirty and clean after you get a look.

 

[mikecr]

Why do you think it's a pressure rise that causes velocity to go up?

 

[BoydAllen]

My take on this is different than the one previously stated. I believe that carbon builds up at the end of the neck part of the chamber because a patch or brush cannot easily reach that location, because of its shape. On the other hand, the area immediately to the rear of this location is generally kept clean by ordinary cleaning. For this reason, I think that having a large enough gap between the end of the neck and the end of the chamber pretty much solves the problem. If the neck ends where normal cleaning works, there is no functional problem, and the pileup down in the corner generally does not get big enough to cause a problem for the passage of the bullet, being limited in its size by normal cleaning.

There is however one location where carbon may build up, depending on the particular barrel, type of powder, cleaning frequency, and method. That is right at the beginning of the leade angle of the throat, just in front of the neck part of the chamber. I have not had this happen with my 6PPC barrels, but a friend did on a match grade 6BR varmint barrel, that went much longer between cleanings. Switching from Tac to 135 solved his problem. I should mention that he has a bore scope, and that the only thing that worked to remove the carbon was Iosso on a nylon brush. JB on a patch did not. Many times discussions of hard carbon are really reports on removing more resistant powder fouling. The stuff that he was dealing with was a whole other animal, harder than what it was attached to, and extremely well bonded, essentially of one piece.

 

[PGS]

Hi Guys, had a look down the barrel with a borescope. There is a black ring of carbon in the chamber at the end of the case neck. The start of the lands look pretty good, there is some faint firecracking but it does'nt look to rough. There is some carbon buildup in one of the grooves a bout an inch from the lands and runs about six inches down the bore. I will use your suggestions on cleaning of these carbon problems and thanks for your help.

with regards

 

[fdshuster]

gunny: I learned a hard lesson about carbon buildup last Summer with one of my 6ppc chamberings. I had just mounted a McMillan Edge stock on the rifle and it began shooting exceptionally well, and I let my shooting get ahead of cleaning. My standard load that had performed trouble-free for almost 10 yrs. suddenly started blowing primers, damaged the Neil Jones built trigger ($70 to repair), and then I checked it with my borescope. Found a ring of carbon in the gap in front of the case mouth. Cleaned it out with JB and a bronze brush, am now keeping after it, and never had a repeat of the problem.

 

[BoydAllen]

Gunny,
If you use a .25 caliber nylon brush, and load the bristles full of Iosso, you can stop it right where you feel it come to the end of the case neck, grab the rod, and twist it round and round several times, for a dirty one, about a dozen times. then reverse the brush ( you can do this with nylon.) remove it, clean out the Iosso with solvent, dry, and then rescope. Let us know what your results are.

 

[Dgd6mm]

Gunny, if you use a boreguide depending on lenght and contour it may cover some of the carbon ring area. I know because of before and after boresoping and polishing. I polish my 6CM every 200 or so rounds. I use a .243 nylon brush with Iosso on a patch with some Kroil, wrap the patch on the brush and do as BoydAllen said.

 

[jelenko]

My take on this is different than the one previously stated. I believe that carbon builds up at the end of the neck part of the chamber because a patch or brush cannot easily reach that location, because of its shape. On the other hand, the area immediately to the rear of this location is generally kept clean by ordinary cleaning. For this reason, I think that having a large enough gap between the end of the neck and the end of the chamber pretty much solves the problem. If the neck ends where normal cleaning works, there is no functional problem, and the pileup down in the corner generally does not get big enough to cause a problem for the passage of the bullet, being limited in its size by normal cleaning.

There is however one location where carbon may build up, depending on the particular barrel, type of powder, cleaning frequency, and method. That is right at the beginning of the leade angle of the throat, just in front of the neck part of the chamber. I have not had this happen with my 6PPC barrels, but a friend did on a match grade 6BR varmint barrel, that went much longer between cleanings. Switching from Tac to 135 solved his problem. I should mention that he has a bore scope, and that the only thing that worked to remove the carbon was Iosso on a nylon brush. JB on a patch did not. Many times discussions of hard carbon are really reports on removing more resistant powder fouling. The stuff that he was dealing with was a whole other animal, harder than what it was attached to, and extremely well bonded, essentially of one piece.

I'm resurrecting this thread because I think in other barrel cleaning threads there is miscommunication because what is called a carbon ring can be either in the gap in the chamber between the end of the neck and the end of the chamber or on the very start of the throat - just as Boyd has pointed out.

95+ % of my experience shooting a rifle is with an AR in 223 wylde.

From my own experience I've never seen a carbon ring in the gap - only at the beginning of the throat.
I have no experience at what it takes to clean the carbon in that gap but have tons of experience removing the carbon ring at the beginning of the throat just before the rifling starts. I've found that only an abrasive will remove the carbon ring on the beginning of the throat just before the rifling starts.
I do use an AR 15 chamber brush with a solvent after reach range session - maybe that's keeping the gap clean.

I have also found a ring of carbon starts to appear on the start of the throat after relatively few shots - certainly by 60.

I'm a bit puzzled by the lack of discussion in other threads on removing the carbon ring at the start of the throat - almost all of the discussion seems to be about the gap between the end of the case and the end of the chamber => does that mean that very few people even get a carbon ring at the beginning of the throat?



The reason

 

[clowdis]

Funny how definitions change over the years isn't it?

 

[BoydAllen]

I'm resurrecting this thread because I think in other barrel cleaning threads there is miscommunication because what is called a carbon ring can be either in the gap in the chamber between the end of the neck and the end of the chamber or on the very start of the throat - just as Boyd has pointed out.

95+ % of my experience shooting a rifle is with an AR in 223 wylde.

From my own experience I've never seen a carbon ring in the gap - only at the beginning of the throat.
I have no experience at what it takes to clean the carbon in that gap but have tons of experience removing the carbon ring at the beginning of the throat just before the rifling starts. I've found that only an abrasive will remove the carbon ring on the beginning of the throat just before the rifling starts.
I do use an AR 15 chamber brush with a solvent after reach range session - maybe that's keeping the gap clean.

I have also found a ring of carbon starts to appear on the start of the throat after relatively few shots - certainly by 60.

I'm a bit puzzled by the lack of discussion in other threads on removing the carbon ring at the start of the throat - almost all of the discussion seems to be about the gap between the end of the case and the end of the chamber => does that mean that very few people even get a carbon ring at the beginning of the throat?

I'm resurrecting this thread because I think in other barrel cleaning threads there is miscommunication because what is called a carbon ring can be either in the gap in the chamber between the end of the neck and the end of the chamber or on the very start of the throat - just as Boyd has pointed out.

95+ % of my experience shooting a rifle is with an AR in 223 wylde.

From my own experience I've never seen a carbon ring in the gap - only at the beginning of the throat.
I have no experience at what it takes to clean the carbon in that gap but have tons of experience removing the carbon ring at the beginning of the throat just before the rifling starts. I've found that only an abrasive will remove the carbon ring on the beginning of the throat just before the rifling starts.
I do use an AR 15 chamber brush with a solvent after reach range session - maybe that's keeping the gap clean.

I have also found a ring of carbon starts to appear on the start of the throat after relatively few shots - certainly by 60.

I'm a bit puzzled by the lack of discussion in other threads on removing the carbon ring at the start of the throat - almost all of the discussion seems to be about the gap between the end of the case and the end of the chamber => does that mean that very few people even get a carbon ring at the beginning of the throat?



The reason

On cleaning at the beginning of the throat, have you tried Thorroclean and Thorroflush? I apply the Thorroclean a little differently than the instructions. The results on one very dirty barrel were, to me, impressive. I think that you are right about why you have a clean gap.

 

[jelenko]

Thorroclean and Thorroflush

Boyd - I haven't. Simply because I'm not wanting to have to buy Thorroflush to get the Thorroclean.
Are you finding the Thorroclean works better/faster than Iosso?

Recently, I've started ignoring the directions on Iosso to 'use sparingly'. Getting the patch 'saturated' with the Iosso paste, has reduced the number of patches with Iosso needed by ~ 30%.
I'm doubling over a patch with the Iosso on a parker hale to get a nice tight fit. 10 in/out cycles for each Iosso patch.

 

[BoydAllen]

Boyd - I haven't. Simply because I'm not wanting to have to buy Thorroflush to get the Thorroclean.
Are you finding the Thorroclean works better/faster than Iosso?

Recently, I've started ignoring the directions on Iosso to 'use sparingly'. Getting the patch 'saturated' with the Iosso paste, has reduced the number of patches with Iosso needed by ~ 30%.
I'm doubling over a patch with the Iosso on a parker hale to get a nice tight fit. 10 in/out cycles for each Iosso patch.

Sounds like you have a good method. Thanks for sharing it.

 

[Murray Brook]

@jelenko
Have you tried Fritz ( green stuff) on a carbon ring or carbon between the lands. I find it better than Iosso.

 

[jelenko]

@jelenko
Have you tried Fritz ( green stuff) on a carbon ring or carbon between the lands. I find it better than Iosso.

Great question.
I have and found Flitz [green stuff] worked better than Iosso UNTIL I started saturating a folded over patch with Iosso. I put as much Iosso on the patch as it can absorb. Using this approach, Iosso is now getting rid of the carbon faster than Flitz.