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Discussion Starter · #1 · (Edited)
There seemed to be enough interest in another thread regarding carbon rings and their effects on 22lr accuracy, that I thought I'd start another thread dedicated to it.

First of all, I'd like to explain that I am not an industry expert. Nor do I have a degree in anything carbon ring related. All I have is my personal experience and what I have read. I am the kind of person that if told something, or I read it, I like to verify that information with personal experience.

Here's what I've learned, take it for what it's worth.. I'll do my best to cover the 3 subjects below.

What is a carbon ring in a 22lr rimfire?

What effect does a carbon ring have?

How to get rid of a carbon ring?

About 4 years ago I became involved in competetive shooting, specifically 22lr. Even though Ive owned and shot a 22 since I was 11, I had only thought about cleaning it when it wouldn't properly cycle and return to battery. (Marlin model 60) That is until I got into competetive shooting. My first competition rifle was a CZ 455 Varmint. I got really lucky, in that it was a real shooter! That Is, it was a shooter until I got about a brick through it! Then something weird happened.. At my matches, after the rifle sat idle between stages, the first shot would hit high left, about an inch from the rest of the string if we were shooting 100 yds targets. If shooting a closer target, say 50 yds, it might be only a half inch high and left. I scratched my head over it and searched the internet until I found an article written by someone (Steve Boelter) that sounded like he knew what he was talking about. In the article, the gentleman talked about a carbon and lead buildup in the chamber of a 22lr. That buildup gets thicker and thicker until it swages the bullet as it is chambered. Here's the part that didn't make any sense to me and made me buy a borescope to literally "see" for myself what was going on. He said that after the first round is swaged and fired and subsequently misses the POA, the "ring" gets heated enough that it softens and won't swage the following shots of a string of fire. First, he described exactly what I was experiencing. And second, how could carbon and lead soften from one shot? So, I bought a Lyman borescope and took a look in my chamber. Sure enough, there was a very definite buildup of jagged black nastiness right about where the end of a case would be in the chamber. So, to test the theory, I soaked, scrubbed and cleaned until I saw nothing but bright shiny metal in the chamber.

I couldn't wait to go to the range and see what effect, if any, cleaning had on the "cold bore" fliers that I had been experiencing. So, off to the range I went. After about 15 or 20 shots to refoul the bore, I was back to my normal accuracy. Now it was time to wait for things to cool down. In my matches, there would be anywhere from about 15 minutes to a half hour between stages, so I found something else to do for a half hour... After the wait, I loaded a mag and chambered a round. Took aim at a paper target at 50 yds and fired. Okay, first shot seemed to go where I wanted it to. So I fired 9 more. All in a nice tight group without any fliers! Boy, was I relieved. I repeated the "wait and cool" experiment several more times that day and every group was without the exagerated flier that I had been experiencing. I was stoked! I had no idea how many points I had missed out on because of those cold bore fliers, but I had them figured out now!

Now that I owned a borescope, I used the heck out of it to check the results of my cleaning. I was never finished cleaning until the last speck of the ring was gone!

One thing I'd like to add to what the gentleman wrote in that fateful article... I don't know exactly what the chemical composition of a 22lr carbon ring is, but I can tell you this after paying attention for several years now. The lube on our match grade bullets is a big part of the equation! A very BIG part! I noticed this after having watched "normal" rings grow from shooting matches. Then, I bought my first Lilja barrel. After installing it and taking it to the range to ammo test it with multiple brands and grades of ammo, I looked in the chamber and there was the nastiest ring I had ever seen! It litterally looked like jagged, bubbly, solidified lava! I thought maybe it had something to do with the new barrel. Maybe I hadn't cleaned it well enough before shooting, or something. So, I cleaned it back to bright shiny metal, went back to the range and repeated the test. Same carbon ring result! So I cleaned it and went back to the range, fired the same number of rounds, but only one brand of ammo. I wanted to see if the mixing of lubes was causing it. So, there was a ring, but it was a "normal" looking ring. So I cleaned my rifle again, went back to the range, fired an equal number of rounds, all of another brand, and again, normal ring. Cleaned it, went back to the range, and shot a mix of ammo brands and the nasty ring was back.

This experiment taught me 2 things..
1. When ammo testing, only shoot 1 brand of ammo at a time, and just swabbing the barrel prior to swtching brands/lubes, does very little to prevent the "nasty ring"!
2. This is the most important thing that I learned. At least to me it is. Carbon rings are not JUST lead from the bullet and carbon from the combustion process shooting multiple rounds. Carbon rings are heavily effected by the lube on our bullets. A carbon ring will build without lubed bullets, but the lube contributes to the ring in it's own way.

When I said that lube contributes to the ring, I would also add that the type of lube on the different brands of ammo builds up at different rates! I started tracking how many rounds I could fire before I would start experiencing cold bore fliers. What I discovered is that my then favorite brand of ammo, RWS R50, would allow me close to 150 rounds before things would go south. Lapua CenterX will go twice as many shots before I experience fliers. It's actually a little more than twice as many. I can get about 325ish shots down range before I see fliers. I haven't experimented with Eley, but I would expect something similar to R50, since their lube is more waxy like R50's.

The next subject is "what effect does a ring have on a round/shot taken"?

I have come to think of a carbon ring as something like cooking sugar. By that I mean that, if you've ever been in the kitchen when someone is making carmeled popcorn balls, you heat up a bunch of sugary ingredients to the point of it becoming liquified. It cant get too hot, or when it cools it will be too hard and brittle. But with sugar that is brittle, it can be reheated until it becomes malleable or even liquid if you really get after it. However, when it cools it will harden and be brittle again. Carbon rings behave in a similar way. When hot, they are malleable, when cool they are very hard.

So, with a well built up and hard ring in your chamber, when you chamber a bullet it gets squeezed and shaped as it passes over or through the ring. You end up with a deformed bullet that doesn't have the same aerodynamic characteristics of a nice, pristine, concentric bullet would. If squeezed enough, it may not seal the chamber and you'll lose pressure. I can only hypothesize why these deformed bullets tend to hit the target at a relatively consistent POI away from POA. But in my experience, they do tend to do just that.
Anyway, back to the ring's effects.. After that first shot, the ring gets warmed enough that it doesnt squeeze or swage subsequent shots in the string and the shots group normally. Let things cool down and you're back to the first round rebel straying away from the norm.

Methods for cleaning a carbon ring is something that I've laughed, cringed, and rejoiced over.

During my "battle" of carbon rings over the years, I've tried a lot of things to get rid of them. It was a mechanical battle at first. Sometimes it took inordinate amounts of standard bore solvent and brushing to get rid of one. I thoroughly understood how a person could do more harm cleaning their rifle than by firing it ever would! There had to be a better way... I stumbled on to what I feel is the best way when I consulted Don Smith (djdilliodon) to see what he recommended for cleaning rimfire rifles. He suggested a product called Bore Tech Rimfire Blend. So, I bought some and tried it. I have to say that it smelled awesome, kind of citrusy. But it didn't do any more damage to a carbon ring than Hoppes or Butches Bore Shine did. At least it smelled better! Then as I was perusing a local Scheels gun department, I saw a bottle of Bore Tech C4 Carbon remover on a shelf, so I bought it just to see if it worked like it said it does on the label. To make a story short, I found my Excaliber to fight carbon rings. Wet a patch, insert it into the chamber, leave it to soak for 15 minutes or so and it totally disolves to ring! NO MORE SCRUBBING!! Occasionally I have to do a second soak, but I never have to scrub now. And to me, the fewer passes of a cleaning rod in my barrel, all the better. Less chance of damaging a crown or throat or...

Borescopes... If you care about ultimate accuracy, and you don't own a borescope, I highly recommend that you get one. If for no other reason, just to keep tabs on the effects of your cleaning regiment. They come in handy for inspecting crowns and all kinds of things not gun related as well.

I started off with a Lyman. It will allow you to see everything that you need to in a barrel. Ive since upgraded to a Hawkeye. DJ's hawkeye to be precise.. Thanks again Don! It really doesn't matter what scope you get, but I do recommend that it is capable of a 90° view so that you look straight down on your chamber or bore. I can't make things out as well if I'm looking straight down the pipe. YMMV
 

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That is a good writeup and I enjoyed reading it. From what you say the carbon ring could have an effect on a sporting type or Bentz chamber over a true match chamber where the bullet is inserted into the rifling. You explained it really well regarding the hard/soft effect the carbon ring has on the bullet/projectile.

But, I say it doesn't affect a match camber because even though the bullet passes over the carbon ring, and for the sake of debating, let's say the bullet is swaged .0001" "honestly it can't be much anyway", when the bullet engages the rifling it will become swaged even smaller negating all the swaging the carbon ring would ever do. This is why I don't think the carbon ring has any effect on accuracy "in a match chamber". That bullet will always start out in the in rifling. At least that's been my experience and belief. But, again, I can see where a sporting type chamber can be affected by the carbon ring.

Thanks for taking the time to explain your experience and thoughts.
 

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Nicely presented!

So you are saying with R50 and CX you see these carbon ring formations after approx. 100-300 shots?

If the carbon ring is already present in the barrel, the only time you see the first shot flyer it is if the barrel has had time to cool down, correct? If you go out and shoot 5-10 warm-up shots and follow that up with approx. 50-100 shots but do not let the barrel cool down then you wouldn't see the effect due to the carbon ring remaining soft?
 

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I remember removing only one carbon ring in ~15,000 rounds of shooting, and it was a very visible ring when looking into the chamber.
I used a small dental pick and a brush and it came out. It's the only one I have dealt with so far. Most of my shooting is done with cci sv, but I believe the ring was formed with federal ammo. We shot a brick through the gun in one sitting and it was semi auto.

I'll bet that certain brands of ammo are worse than others and that semi auto might build a ring faster than bolt action.
 

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RickBaum has given a very good explanation of the carbon ring problem. His observation at the end that he "can't make things out as well if I'm looking straight down the pipe" is important and well worth remembering. No one can make out much if anything of importance -- even the beginning of a carbon ring -- by simply looking down a bore.

Here's a little more detail on how the carbon ring develops from an explantion by Steve Boelter in his excellent and detailed essay on rimfire cleaning, from which, incidentally, the revealing picture of the carbon ring shown above is taken:

During the initial combustion of the round, burning gasses loaded with various bit of fouling blast out from the case mouth right when the bullet leaves the case. At the point where the bullet has just separated from the case mouth, hot gases consisting of burning powder (carbon), a tiny amount of vaporized lead from the base of the bullet, and burnt primer material blast into the chamber's throat.

At this point, the gases are at their peak temperature and reaching their max pressure. As this mixture is blasted into the chamber's throat, it quickly cools and some of this fouling begins to stick.

Since the bullet is actually traveling in front of this hot mess of gasses (it has already started down the barrel) the fouling continues to build up in this area faster than anywhere else in the barrel.

The lead bullet is not pushing out the fouling in this area.

Subsequent firings continue to build until this ring begins to actually touch the bullet itself, which can either push the bullet off-center in the chamber or act as a giant speed bump for the bullet to squeeze past before it starts down the barrel.


See http://www.ssvtexel.nl/index.cfm?act=files.download&ui=C5C9D865-2200-0A21-B5F5CF897974784F

Boelter notes that BR shooters focus on the chamber and first few inches of the barrel when they clean because a carbon ring can cause a gradual decline in accuracy.

You may have heard [the] shooting term referred to as the "window" of accuracy. This window represents a range of fouling in the barrel where the rifle shoots the best. Typically at the end of this range, the black ring is starting to impinge on the bullet by pressing into the bullet's side, or the fouling has grown into a long sticky mess which grabs at the bullet when it passes by.

According to Boelter,

In sporting rifles with large chambers, it can take a long time for this fouling ring to built to the point where it begins to contact the bullet when chambered. In target rifles, it can be noticed within a single shooting session.

The carbon ring is worth paying attention to, especially when shooting for the best accuracy with your rifle, and especially so if using a rifle with a match chamber.
 

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Discussion Starter · #7 ·
That is a good writeup and I enjoyed reading it. From what you say the carbon ring could have an effect on a sporting type or Bentz chamber over a true match chamber where the bullet is inserted into the rifling. You explained it really well regarding the hard/soft effect the carbon ring has on the bullet/projectile.

But, I say it doesn't affect a match camber because even though the bullet passes over the carbon ring, and for the sake of debating, let's say the bullet is swaged .0001" "honestly it can't be much anyway", when the bullet engages the rifling it will become swaged even smaller negating all the swaging the carbon ring would ever do. This is why I don't think the carbon ring has any effect on accuracy "in a match chamber". That bullet will always start out in the in rifling. At least that's been my experience and belief. But, again, I can see where a sporting type chamber can be affected by the carbon ring.

Thanks for taking the time to explain your experience and thoughts.
Thanks KOD.. I just hope it helps someone.

In regards to your comment about chambers. My experience leads me to me to believe that the tighter the specs of a chamber are, the sooner that the ring will affect accuracy. I've now paid attention to multiple CZ and Tikka sporter chambers, 3 Kidd chambers (whatever they are..), 2 of Lilja's Bentz chambers, 2 of DJ's custom spec'd chambers, an Eley EPS Match chamber, one of Lilja's original Match chambers, and 2 of Lilja's new Lilja 2 chambers. What I would guess is that the extra room of the sporter chambers leaves more room around the chamber for the ring to grow before it swages the bullet. One of my sporter chambered barrels has gone over 650 rounds and still no fliers. Maybe it's just dumb luck. However, sporter chambers have proven to go much longer, in general, than match chambers have, in my experience.
 

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Discussion Starter · #8 · (Edited)
Nicely presented!

So you are saying with R50 and CX you see these carbon ring formations after approx. 100-300 shots?

If the carbon ring is already present in the barrel, the only time you see the first shot flyer it is if the barrel has had time to cool down, correct? If you go out and shoot 5-10 warm-up shots and follow that up with approx. 50-100 shots but do not let the barrel cool down then you wouldn't see the effect due to the carbon ring remaining soft?
Correct. I'm editing to add that my comments are solely about this one particular type of flier. Other acts of random POI can and will manifest from any number of other possible causes.
 

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Discussion Starter · #9 ·
RickBaum has given a very good explanation of the carbon ring problem. His observation at the end that he "can't make things out as well if I'm looking straight down the pipe" is important and well worth remembering. No one can make out much if anything of importance -- even the beginning of a carbon ring -- by simply looking down a bore.

Here's a little more detail on how the carbon ring develops from an explantion by Steve Boelter in his excellent and detailed essay on rimfire cleaning, from which, incidentally, the revealing picture of the carbon ring shown above is taken:

During the initial combustion of the round, burning gasses loaded with various bit of fouling blast out from the case mouth right when the bullet leaves the case. At the point where the bullet has just separated from the case mouth, hot gases consisting of burning powder (carbon), a tiny amount of vaporized lead from the base of the bullet, and burnt primer material blast into the chamber's throat.

At this point, the gases are at their peak temperature and reaching their max pressure. As this mixture is blasted into the chamber's throat, it quickly cools and some of this fouling begins to stick.

Since the bullet is actually traveling in front of this hot mess of gasses (it has already started down the barrel) the fouling continues to build up in this area faster than anywhere else in the barrel.

The lead bullet is not pushing out the fouling in this area.

Subsequent firings continue to build until this ring begins to actually touch the bullet itself, which can either push the bullet off-center in the chamber or act as a giant speed bump for the bullet to squeeze past before it starts down the barrel.


See http://www.ssvtexel.nl/index.cfm?act=files.download&ui=C5C9D865-2200-0A21-B5F5CF897974784F

Boelter notes that BR shooters focus on the chamber and first few inches of the barrel when they clean because a carbon ring can cause a gradual decline in accuracy.

You may have heard [the] shooting term referred to as the "window" of accuracy. This window represents a range of fouling in the barrel where the rifle shoots the best. Typically at the end of this range, the black ring is starting to impinge on the bullet by pressing into the bullet's side, or the fouling has grown into a long sticky mess which grabs at the bullet when it passes by.

According to Boelter,

In sporting rifles with large chambers, it can take a long time for this fouling ring to built to the point where it begins to contact the bullet when chambered. In target rifles, it can be noticed within a single shooting session.

The carbon ring is worth paying attention to, especially when shooting for the best accuracy with your rifle, and especially so if using a rifle with a match chamber.
Thank you for posting that Penage! That is the article that got me started in all of this carbon ring curiosity/rabbit hole. Lol

I'm truely grateful that you posted that!
 

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Discussion Starter · #10 ·
Another thing that came to mind while reading Penage's exerpts from Mr Boelters essay..

I have yet to see a carbon ring that is evenly formed all the way around the chamber. Some have said that it will "always form the thickest at the 6 o'clock position".. Not in my experience. In that person's defense, it may form the heaviest at 6 o'clock in his particular rifle. My current match rifle forms them the thickest at about 2 o'clock.

Not sure what my point is, but I guess that If a bullet is being swaged in one particular spot more than anywhere else, maybe it has something to do with the consistency of where the cold bore shot impacts relative to the rest of the string? I dunno.
 

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Very good stuff :bthumb:
Looks like the best time to get that carbon cutter fluid in that throat is right after shooting while the ring is still warm and as soft as it will be. Maybe leave a Q-Tip wet with it in there until home and wipe it out?
 

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Discussion Starter · #12 ·
Very good stuff :bthumb:
Looks like the best time to get that carbon cutter fluid in that throat is right after shooting while the ring is still warm and as soft as it will be. Maybe leave a Q-Tip wet with it in there until home and wipe it out?
Maybe... Wouldn't hurt to give it a try.

However, if doing it that way doesn't work out for you. I know that the Bore Tech C4 Carbon Remover that I mentioned in my original post disolves it no matter the barrel temperature.. Well, at least down to 34°, anyway. I took my cleaning kit to a match last week and cleaned a gentleman's rifle for him while there. It was 34° and it melted the ring like butter. It was a 5 month, 1250 round carbon ring. I would say that it had developed just a tad past a normal gestation period! ;) :D. That one took 2 soakings to get it out.
 

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Discussion Starter · #14 · (Edited)
Great info. Thanks for sharing your knowledge. Just ordered some C4 .
Thank you, Sir! I seriously just hope that it helps folks. There's nothing more frustrating than trying to figure out a misbehaving rimfire!:)

Let us know how it works for you. I think you're going to like what it does.

Do you have access to a borescope to see the condition of your chamber before cleaning and then to verify results?
 

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Thank you, Sir! I seriously just hope that it helps folks. There's nothing more frustrating than trying to figure out a misbehaving rimfire!:)

Let us know how it works for you. I think you're going to like what it does.

Do you have access to a borescope to see the condition of your chamber before cleaning and then to verify results?
No Rick, I don't have a borescope. Just a good set of loops. I'll try to get as good a view of it as possible before and after.
 

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I enjoyed the read, I do not have a borescope and realize I need one, that is on my buy list. Carbon rings do exist and as stated earlier they can be a bugger to get out, I will be trying the carbon remover mentioned by Mr. Baum. I shoot more than most, and this is what I have observed. Match chambers, standard chambers, all .22 caliber chambers will develop carbon rings. Some much faster than others. I've always used a 6MM bronze core brass brush on a pistol rod to scrub out carbon rings with no ill effects to the barrels. One little 541-s that I owned needed cleaning at about 1000 rounds, determined by the groups, when they began getting bigger, I scrubbed it out, I'd be hesitant to guess the thousands of rounds that went through that barrel and its still a very accurate rifle. I have one Anschutz that will approach 500 rounds before it needs scrubbed, then it will take 50 rounds to settle down and shoot bug hole groups. Another Anschutz is good to go 250 rounds before it requires scrubbing out. I agree also that the waxy lubes will cause earlier problems. Waxy lubes can cause extraction/ejection problems, its sticky. There is no way that I'm aware of to know which chambers will allow more shots before the carbon ring affects accuracy.

This may be a little off the wall, but I believe a fairly large percentage of new rifles have a tiny burr at the end of the chamber and that tiny burr causes lots of rifles to be deemed unworthy, poor shooters. I have had two new expensive rimfires that I was ready to get rid of, I think every shot that you fire leaves a tiny amount of lead attached to the burr, it grows with every shot, a few good groups and it starts scattering them. If you keep shooting it and cleaning it, it will eventually smooth out and suddenly shoot lights out. Don't give up on a good rifle too soon.

This is all conjecture on my part, or what has worked for me, thanks for reading.
 

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And just to mess with RB, I like my carbon ring. :rolleyes:

No, seriously, in my antique Model 60, it is more accurate with the ring.
Why? Not positive, but I think it tightens up the chamber and provides a better fit to the cartridges.
Keeps them from moving around once the bolt slaps back.
This gives me more consistent results...for a 45 year old semiauto squirrel rifle. :D

My Shilen and Liljas get scrubbed after 250 to 300 rounds.
If I don't, I get extraction problems. Feels like the case mouth flares
and bites into the ring causing the brass to stick in place.
 

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i have tried c4, and got the thing to where i could only get clean patches out of it. then, i soaked the clean barrel in a mix of hoppes and kroil and scrubbed it with a 6mm brush. i was amazed that i was able to get fully black patches out with hoppes/kroil after the c4 was done. i dont know why. i had great expectations when i bought the big bottle of c4, but it just didnt work as expected for me.
 
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