Educate me on this infamous thing called a Carbon Ring.

[mtnbound]

I grew up in a family of hunters and shooters, and I have been shooting for decades with various cartridges and have never experienced a Carbon Ring buildup in a chamber. Yet I see it mentioned fairly regularly. I do not clean my rifles (other than black powder ones), and I have not cleaned them for a long time, so, in my experience, it's not caused by lack of cleaning. I have no supporting evidence, but I believe most people actually clean their rifles because it's always been done that way. I watched a guy at the range recently clean his rifle after every 4 shots. When asked why, he said it was to reduce carbon buildup and improve accuracy. I said ok and went back to shooting my uncleaned 223 rifle.

Is this carbon buildup from a particular powder manufacturer, powder burn rate, powder volume used in a case, shooting too little, shooting too much, weather, using inappropriate cleaning products, aliens, or what? I have a hard time believing that I, or anyone else in my circle, have just been lucky and never experienced one.

 

[kswaterfowl]

I could be wrong, but it sounds like an issue with barrels that have tight chambers.

 

[akhunter3]

My understanding was this mainly impacted fancy custom rigs with extremely tight chamber tolerances

 

[Dave Thomas]

If you're not cleaning your rifle you will have a carbon ring. It might not cause you any problems but it's there. Look in your barrel with a borescope and you'll see it.

 

[Wrench]

Imagine shooting through a doughnut made of incredibly hard grit. Every shot adds copper and carbon. At some point the hole in the doughnut gets smaller than the bullet is in diameter and strips the bullet which eventually stops the rifling from working in extreme cases.

 

[Gadjet]

I believe it's mainly a PRC thing. In other words, cartridges designed with tighter than average tolerances. I have a 7PRC and it builds up a carbon ring.

 

[SBR Sarge]

Only example I have experienced was in a 357 revolver shot a lot with 38 spl loads.

The 357 loads ended up not chambering until the ring was scrubbed out.

 

[83cj-7]

Not every barrel gets a carbon ring because of not cleaning or being abused. My Krieger 8 twist .243 barrel wasn’t cleaned for 700+ rounds and there was no carbon ring at all. Oddly it didn’t change one thing after cleaning it.

I do know someone that has a 6 CM barrel that develops a carbon ring every 100 or so rounds and accuracy goes to crap. I told him that I’d unscrew that thing and use it as a tomato stake before going through all that BS.

 

[Kimber7man]

Is it due to increased use of suppressors?

 

[270-300]

I shoot vintage hunting rifles. Never had a problem. Once a year or so i run a hopps 9 patch and let it sit an hour. Then run a bronze brush a few strokes, then a hopps patch, then a ballistol patch, then a dry patch. Get a lot of soot and powder fouling out, not much else.

The bore scope guys tell me that as barrels wear they get scorched rough patches just past the chamber. They tell me this rubs copper off the bullets. Well i would think it would only do so a few times until this copper fouling seals it.

Of course it depends on how one shoots. I dont pump off boxes at the range. Most of my rifles see less than 10 shots a year.

Theres guys on here who talk constantly about how they wont shoot a lot of older cartridges because they claim the barrels will be burned up in under 1000 shots and for them thats only a few months.
Aside from ww2 milsurps that were counter bored, ive never seen someone prove to me a rifle was shot out. Ive seen several people who could not shoot their rifle well tell me this, and then proceeded to shoot clover leafs at 200 yards for them.


I remember one of the vortex podcasts a couple years ago about burning out barrels, and they had a couple test rifles they use that they said had some crazy high round counts, many times more than the accepted barrel life of those calibers, that still shot better than 90% of the people on here can.

Ive always felt most of these rifle barrel issues are in the categories of people who dont shoot and heard it from someone, and people who shoot like crap and think they sound like a pro if all their bad shooting is from some factor of shooting 30x more than most people who actually shoot.

 

[swavescatter]

I was in the no-clean camp until I had my 6.5 PRC start popping primers and not even be able to chamber a round due to carbon fouling. Noticed it in my 243 as well as a 6.5 Creed. Couple factors I believe contribute:

• Overbore cartridges or hot handloads that have lots of powder being ejected
• Use of high back-pressure suppressors
• Cases trimmed too short leaving room between the case mouth and chamber edge

I could probably fix the issue by backing down my handloads, but I'm OK just giving a good bore scrub every 100 rounds or so when the issues show up. Still don't clean other rifles but I'll watch for any issues and clean as needed.

Factory ammo with 308 or 223? Doubt you'll ever see it.

 

[Quandary]

Do you have a bore scope? If not there you no way you can say I have never had a carbon ring. As stated above you may but just don't notice it in the performance of the rifle.

I find that rifles which are over bored tend to develop carbon rings more readily than non-over bored rifles. For example my 7PRC seems to develop carbon rings while my 35 Whelen does not. If you stay on top of them and clean them up before they get to bad they are easy to manage. Only way to know is either with a bore scope or a sudden increase in velocity or loss of accuracy. With respect to velocity you will only know if you routinely use a chronological when shooting.

 

[beerbucksducks]

I had a bad one build up on my Christensen 6.5cm. I cleaned the piss out of it with 2 different carbon cleaners, brushes, iosso and kroil, you name it and it wouldn’t come out. The gunsmith had to hand turn his reamer to cut it out. I never had a borescope before hand, so I don’t know when it started but the last few hundred rounds were all suppressed. The gunsmith did say it was the cleanest Christensen barrel he had seen. I’m still not sure what caused it, but I’ll periodically clean with boretech to avoid the issue.


Sent from my iPhone using Tapatalk

 

[Quandary]

If you have a tough one in the future try a tight fitting chamber or bore mop soaked with Boretech C4. Leave it in the chamber overnight, then attack with a bronze brush. Repeat if necessary. If its really bad take the barrel off use the soaked mop approach. Then use a bronze brush attached to a electric drill.

 

[83cj-7]

@270-300

I’m glad you have good luck with your barrels but believe me, you can shoot out a barrel in short order. There are a lot of factors. Powder, barrel steel, how hot you run it etc. I have shot out a .243 barrel in 600 rounds and a 6x45 barrel in 500 rounds. I believe both of them had something wrong with the steel itself which caused them to burn out quickly. When I say shot out, I’m talking about being able to push a bullet 3/4” up in the throat, like nothing left at all, and confirmed with a bore scope. In my 243 barrels I have found that H4350 was a major factor to killing them too quickly. Now that I have been running H1000, I’m past 2000 rounds with only minor throat wear and a tiny amount of checking.

 

[Chris in TN]

It's a real thing, for sure. Why it develops in some rifles but not others, I cannot say.

Sierra had some literature documenting it even back in the 1990's. They didn't call it a carbon ring, they called it 'hard powder fouling' or something of that nature, and described it almost like a ceramic that developed in higher intensity cartridges.

I think with most rifles the gas pressure is high enough that the rifle sort of self-cleans, like an oven at high heat. I can't say why some individual barrels tend to foul in spite of this. I suspect it's a rough barrel finish that gives carbon a place to stick in the first place, but that's only a guess. But I can say that it doesn't seem to be an issue at all with better barrels (meaning those that have higher interior finishes, regardless of other aspects) and lower intensity cartridges, meaning that if you start with a quality barrel and don't hotrod the thing, it's less of a factor.

 

[Chris in TN]

In my 243 barrels I have found that H4350 was a major factor to killing them too quickly. Now that I have been running H1000, I’m past 2000 rounds with only minor throat wear and a tiny amount of checking.

I've seen this mentioned multiple times.

Do you think this is because of something specific about H4350 or because people tend to run overpressure with it? It's much harder to overpressure H1000 simply because you can't stuff enough in the case. With H4350 you have enough case capacity that I think a lot of guys just make assumptions about when 'pressure signs' will develop, and with good brass that might not start until 65kpsi or more, and they think they're getting a free lunch when in reality they're hotrodding without knowing it.

 

[83cj-7]

I think it’s about flame temp, or whatever the technical term is. H1000 is considered a “cooler” powder. My H4350 load was not anywhere near over pressure.