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Removing Hard Carbon Ring

Hard Carbon

Forums are loaded with practical advice. Unfortunately when it comes to barrel cleaning, I think FUD reigns King. Far too many people cite the adage that barrel cleaning causes more wear and damage than shooting. Someone is always quick to follow up with a confirmation that this is true because of the story their gunsmith told them. While it may not be BS in total, it is BS if you have half a brain and are using current tools.

At this point you can probably tell there is a bit of a rant in this post. You are not wrong. While I personally think it is worth the read, I understand that is likely not why you landed on this page. If you could care less about how I have come to this conclusion and simply want to know how to fix the mess you have on your hands, by all means skip on down to the example and cleaning process.

Let's Get Some Things Straight

We get it, barrels are hard. By comparison, bullets are soft. Therefore anything harder than a soft bullet is going to damage the barrel, right? Let’s be clear on this. Just like water is soft if you stick you finger in a bowl full of it, it is hard as heck if you land on it by falling 50′. Now take that soft bullet. How do you think it feels when it is backed by 55,000 psi and heat that is the temp of the sun? Maybe you are still not there so to take it a bit further, your bullet is larger than the inside of the barrel. It gets squished, elongated, and engraved as it passes down the rifling yet somehow manages to snap back into for so as to fly straight. Still think its soft?

To look at it a different way, slugging a pistol or black powder rifle barrel is a pretty common thing. However, nobody in their right mind does it with a bullet or round ball since the lead is way to hard. Instead we use fishing sinkers or similar soft lead else the bullet may never even make it into the barrel. And if it did, the odds of it getting it stuck is the kind of bet that a casino would love for you to bet against. Now take that same hard bullet and try to force it in the barrel at a speed of 2,800 fps. Got a visual of damage yet?

Okay, so bullets are hard and pressure creates damage. So what. Cleaning rods are the thing that cause all the damage anyway right? Well, yes. This is especially true if you are using the crap rods that came in some bulk cleaning kit. They don’t spin free, assuming the spin at all. They are rough and or have joints that are not flush. And for whatever reason they don’t go down the barrel without bumping into stuff. But wait for it – this is old news and these issues have been solved over and over again by some great companies.

Modern cleaning rods have some killer bearings, and rod guides have all but eliminated rubbing rods on the lands. Sure you can still run the rod past the crown and do some damage out front, but that is solved with technique and is also of little concern if you keep things lubricated. Okay, enough about the FUD on damage being done by cleaning. Not paying attention when cleaning is what causes damage. I can go on about it, but will simply save it for another post.

So what about all the wiz bang solvents that say right on the bottle that they removing carbon? Yup, FUD on that one too. Okay, maybe that is not fair. To be clear, I am talking about hard carbon. The kind of stuff that is crusted and shines. I am not talking about the stuff that turns a patch black. In fact, the carbon I am talking about is the carbon shows no indicators of being present during most cleaning regiments as it is far to hard to be removed.

What is hard carbon, how does it get there, and why is it so hard to remove? And above all, how does it get so bad? Lets think back to grade school. How are diamonds made? Yup, carbon, heat, and pressure. What is in our barrels? Carbon, heat, and pressure. Following? While we there is not practical way that I am aware of to stop carbon, you can minimize the introduction with proper brass prep (more on that later). Not shooting with a hot barrel can help as well but for some of us that is just not realistic. You can also clean well enough and frequently enough using the correct tools to keep it under control. Do you really think that something that is on its way to becoming a diamond is going to melt away with some liquid and get rubbed off with a thin patch or plastic brush? Just in case, the answer is No.

Okay, we agree that carbon is hard and patches and plastic brushes are not. So why not just use a penetrating oil to separate the carbon from the barrel? Well, the carbon is fused to the barrel and no liquid is going to work its way between them. Ever. Don’t worry, I fell for it as well. I have tried just about every gun cleaner, engine cleaner, fuel system cleaner, creeping oil, and witches brew that some other guy said gets the job done. I have even soaked barrels plugged off at both ends with Kroil, Ed’s Red, etc. With possibly one exception, none of it is going to solve this problem, at least without the best case of you being married to your rifle and cleaning kit for a week or longer. As for the exception, I must admit that plugging a barrel and filling it with Berryman Chem-Dip #0996 and letting it sit for about 2 weeks does a fairly decent job of breaking down the hard carbon to where it can be brushed out with a stiff brush and some elbow grease. However, I have only tried this on a wasted barrel that was separated from the action, and I never shot it. Between having to pull the barrel so the rifle can be down for a couple of weeks, and not really knowing the implications of the Berryman, I still consider this an unworkable option. Still, I am playing with soaking a couple of brakes for a week at a time between outings to see if I can pick up on any adverse reaction. Maybe more to come on this one.

Now that we are all knocked back to 3rd grade science when it comes to carbon and diamonds, it may be a good time to dispel a couple of other myths. Shooting a bullet down the barrel is not going to “push” hard carbon out. In case you are wondering, the same goes for a leaded barrel. Anything that is fused inside the barrel is taking up room and the bullet will consider that room as something that it needs to pass, not push. Yes you can get David Tubbs’ TMS bullets, but those bullets are designed to remove material so it is not the same thing. In fact, they remove steel! I am not going to debate the usage of cleaning bullets in this post – I have mixed thoughts about them. The other myth, well maybe more of a misunderstanding, is the damaging carbon ring is the ring that forms right at the edge of your case mouth. While this ring can cause chambering and ejection issues, and worse can can lead to pressure and accuracy problems, it is easily spotted and easily cleared. The ring I am talking about forms inside the rifling and typically starts about 1/2″ – 3/4″ past the start of the lands and extends for about 2″. If you are paying attention you can feel it with your cleaning rod as it causes resistance when passing it. When it is getting really bad, you have to force the patch past it.

So what about the brass prep thing? Ever hear an old bench rest shooter say go thin for the win? What they are talking about is turning necks for clearance. Not the kind of clearance simply to pass a plunk test, but the kind of clearance that allows the bullet to completely release from the brass. A complete release makes it easier for the bullet to ride the tip of the explosion, thus trapping gas and powder behind it where that massive fireball is working to incinerate it. Gas and powder that sneaks in front of the bullet is most likely getting run over by that bullet and pressed into the barrel. As you have likely inferred, an improper load (powder choice or otherwise) will also leave crap in the barrel behind a bullet thus making it so the next bullet has to smash it into the rifling to get past it. Point being, if you handload you can either help or hurt the situation.

It is also worth pointing out that some calibers build hard carbon faster than others. Remember the heat thing? A 308 Winchester has to be abused pretty badly to develop a carbon ring that would cause concern. Between the slower bullet and larger bore diameter that allows heat and gas to dissipate faster, they are just not going to be much of a problem. Fast 223’s (1:7 and 1:8 twist 24+ inch barrels), .243’s, .265’s, especially ones that are running 2,900 fps and faster, are prone to forming carbon rings.

A Practical Example

In order to provide a reasonably comprehensive look at what is going on, I decided to inflict a little harm on a new barrel. Mind you I did not risk damaging the barrel. However, as I will cover later, one of the steps I am going to take is going to cost me some effort later on in order to get you a good look at things.

Note that to get the carbon ring to build fast enough without having to shoot the snot out of the barrel, the reamer used was a no neck turn with new Lapua brass. Although I did turn the necks enough to remove the high spots. Normally I shoot brass that gives a minimum of 0.0030 total clearance around the neck. For this test I used 0.0015 – 0.0020. Translation, while the fired brass was expanded, I could not simply drop a bullet into the expanded case and have it fall in. By drop in, I mean place the bullet in the neck and let go to have it hit the bottom. These would easily push in, just not drop through freely. There is no way the bullet was releasing clean enough to get the best seal.

This 26″ Bartlein 223 Remington barrel has 300 rounds down it. All the loads were pushing a 77 grain SMK with an SD of 2842. It was patched cleaned with Butch’s Bore Shine (BBS) after each of the first 5 rounds, then the next ten. It was also patched any nylon brushed with BBS at the end of the first 100 and second 100 rounds. The photo is prior to cleaning after the third, 100 rounds. It had been sitting for 2 weeks since it was last fired.




The barrel was cleaned as per the above after 300 rounds until the patches came out clean. I then did 3 more cleanings (no additional firing). The patches shown are the result of the following 3 steps: 1) Hoppe’s 9 using green (aggressive) VFG pellets. 2) BBS and a Bore Tech Eliminator (nylon) brush. 3) BBS and a bronze Bore Tech brush. You can see the condition of the barrel after the final cleaning, along with the patches for each of the “special” cleanings. Note that by all indications, even after the VFG pellet and the nylon brush, the barrel is clean. It is not until the bronze brush was used that you can tell that something was left in the barrel. I would have been more than justified to quit after the bronze brush.


Here we get a look at the barrel after the special cleanings. Personally, if I was not experimenting for the purpose of this post and the barrel had a thousand or so rounds down it, I would not mess with the barrel at this point. However, my “normal” cleaning process would not have allowed the carbon to be at this point in only 300 rounds so we are going to keep going. Note the hard carbon, while still present, is very thin and I would fully expect this barrel to still be a tack driver if we stopped here.




Rather than leaving room for the naysayers that would say I did not let the solvent soak long enough, I did a special step just for them. I ran Hoppe’s 9 down the barrel and let it soak overnight. I then wet brushed it with a bronze brush. Not much difference.




Hopefully at this point you have a good understanding of what we are dealing with. I have used 2 of the most popular solvents, patches, pellets, and both known good nylon and brass brushes. I have even let the barrel soak overnight. If the carbon was easily removed the barrel would be clean as can be by this point. Another special note for the naysayers, I have enough of the other chemicals (entire Bore Tech lineup, nearly all of the Wipe Out lineup, foams, etc.) that I can say no matter what I put into the barrel for this example, the results would be nearly identical.

This next part is somewhat controversial in my mind. Paste cleaners. They work, but I believe the popular methods of use are wrong. I also know that using them causes the barrel to copper fowl quickly so they require frequent cleaning during the next outing. Copper fowling is the price I will be paying for the privilege of being able to write this post.

Bore Paste Cleaning Solutions

JB (normal gray and the red “polish”), IOSSO, and Flitz. All of them claim to be non-abrasive. I don’t care what the packages say, they are all abrasive. Now before anyone goes running off thinking I am saying these manufactures are participating in false advertising, I am not. At issue is the aluminum oxide that is commonly used in these types of products. The intent of including them, as far as I can tell, is to cause a chemical reaction. It is not intended to be a scouring compound and the granules used are very fine. Still, aluminum oxide is an abrasive. Mind you this is a good thing so long as you keep your head in the game as to what the consequences can be.

As mentioned, I think some people use these products incorrectly. I frequently read and get told that the way to use them is by wrapping a patch around a worn brush. The patch is coated with the compound, and a lubricant, Kroil for example, is used to both act as a carrier and keep the patch moving. It sounds good, but its a bad idea. Running a compound down the barrel is messing with the edges of the rifling. If you are going to do it, you want full control of the tracking.

A good way I talk about it is think about what would happen to your favorite knife if you took a patch with said compound an oil, and ran it down the edge. The first thought is a bit cringe worthy. Now think about doing it another 19 times. If you managed to keep every pull down the blade straight you would end up with a super polished blade, but you would have also taken a bit of the edge down. Now granted in reality you would have shredded the patch assuming of course it really was a good knife, but that is beside the point. Now think about that same knife, only with every pass slide the knife to the side at random spots. As you can envision, the edge would now be inconsistent. Well that is what happens when you wrap a patch around a brush. The bristles cannot track well enough so the patch moves around causing inconsistent spots in the rifling.

The proper way to use compound is to coat the patch, and then either use a standard jag, or Parker Hale jag, with a lubricant of course. Having a solid jag under the patch allows the patch to track properly so as to have minimum influence on the edges of the grooves. So what does this say for IOSSO and their special blue bristle brushes? Well, in my personal opinion which is based on experience, the blue brush method on the package does not work anywhere near as well as a patch. The brush certainly does not track as well as a patch.

So if compounds are risky why use them? Well, because they work! Just be smart about it. The biggest thing to keep in mind is you only want to work the areas where the carbon is a problem, namely the initial inches of the barrel. If you short stroke the barrel, as in just that, short stokes, and keep it to the bad parts of the barrel then you are going to spare the rest of the barrel from both potential harm and unnecessary copper fowling.

Here we get a look at the first round of JB patches. Starting on the left, the first 2 are JB coated patches with Kroil as the lubricant. The patches were sent straight down and out the barrel. On the far right, bottom, is a third patch with JB and Kroil. The patch was short stroked for the first 4″ of the barrel and then pushed out. The two patches above it were pushed down and out the barrel dry.

Looking at the barrel after a quick JB scrub followed only by 2 dry patches, we can tell the impact is far greater than the bronze brush.

This next set is simply to show that enough, is enough. Despite the barrel being in good order, I went ahead and did another JB run. From left to right, the first and second patches are JB and Kroil down and out, followed by short stroking, followed by a dry patch out. While they are “blacker” than the first JB set, it is mainly attributed to my not flushing out the JB from the first set. Paste cleaners create a shine by oxidizing the surface. I would have had a mess on my hands if I had left the JB in the barrel for hours rather than a few minutes.


Lastly we have the barrel after the final cleaning with JB, patched clean, and flushed with alcohol. You can see there is not much difference between this photo and the result of the first JB set. If you are going to use JB or similar, check your progress frequently and don’t be afraid to call it done early.


There are some additional things to keep in mind when using paste cleaners.

  • When working with compounds, an aluminum bore guide is advised. I have some rather nice Delrin guides from PMA, but I would never used them with compound. You want something this is not going to hold on to the compound.
  • Reapply oil to the patch every couple of strokes. You don’t need much. At issue is the oxidation thickens the compound, which then makes the patch move around on possibly even roll on the jag.
  • JB is non-embedding, where Flitz is, and IOSSO may be. If you are using something that may get embedded spend extra time flushing it, maybe even consider brushing it a few times to help loosen things up. This is especially true if you have firecracking inside the barrel.
  • Brake cleaner, contact cleaner, and alcohol are good for flushing. I prefer alcohol as it does not evaporate a quickly so it is easier to carry the compound down the barrel.
  • Even with the compound being flushed, a light coat of oil will give extra protection against oxidation in case you did not get everything out.

Don't Let Things Get Out of Control

I am a fan of bronze brushes. While I don’t use them in .30 cal barrels very often as they are slower and run cooler, thus not needed as often, I regularly use them on .264 and down. While cleaning frequency is highly debated, I clean every 100 – 200 rounds, which is pretty much after every trip. Mind you that was not always the case. I had never had a problem with hard carbon until I read enough posts telling me why cleaning was bad or just not needed. I was not until after fighting a brutal carbon in a 6 Dasher after just 500 rounds, and crusting the snot out of a 6.5 Creedmoor around 1,000 rounds that I changed my tune and went back to my old ways. It was actually David Tubbs talking about brushes that gave me the incentive to go back to using them. Deep down I had always known better, as in that they should be used, but like many I gave in to the FUD for a time.

So to close this out I will share a couple of photos of a 0.25 MOA 6.5 Creedmoor that opened up to 0.75 at 300 yards because of a carbon ring. The first photo is after brush cleaning with Bore Tech C4, BBS, Wipe Out with the accelerator, and Hoppe’s 9. I was trying to avoid the JB. Note I view paste as a last resort. The second photo is after the JB. While I have not been able to get the rifle to shoot better than 0.38 MOA since, I blame my game, not the barrel.

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