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Barrel fouling and carbon ring- Update

IMG_7010.JPG IMG_7010.JPG I have my fathers older Ruger 6mm Rem that is giving me fits. The barrel had been neglected for years without being properly cleaned until recently. Accuracy was poor and I was not able to get the proper sized patch down the barrel without using a mallet...got stuck halfway down! Went thru some rigorous cleanings with different solvents without much success. Was advised to use JB Bore paste and it made a world of difference and regained accuracy. My problem is it fouls up so bad after a few shots you can't get the regular patch in the barrel. I did the JB cleaning again and the patch goes thru without a problem. I just got one of the teslong Bore scopes and checked out the barrel after cleaning and saw there was still a lot of carbon fouling in the first few inches of the barrel. Hit it one more time with JB and it looks much better. My question is this- is it possible that there was so much carbon build up that even after many cleanings and 2 JB treatments a barrel would get so fouled in 10-12 shots the patch can't get down it? The patch literally gets jammed at the end of my Bore guide. Would something else be causing it? I took a picture of a black ring that is at the end of chamber in front of the rifling. Is this a carbon ring? Sorry for such a long post but this is new to me. I'm a hunter and shoot for fun and just getting into the more precision reloading and barrel cleaning. Many thanks.
 
Suggestion: Cut down the size of that first solvent soaked patch. Generally I am opposed to the use of tight patches. For my 6mms I use a .22 piercing jag and 1 3/8" square patches. Once the barrel gets wet the going should get easier. How are you applying the JB? When you have used it, did you keep going until all of the carbon was removed?
 
Thanks Dusty, will try that!

Boyd, I applied the JB with a jag that allows you to thread on some felt pellets. I put some Kroil on the pellets then put the JB on the pellets and stroked the crap out of the barrel. Being able to see with the bore scope this time before and after I did a lot better job getting the first few inches clean. The rest of the barrel is ok. i must not have got it clean the first 2 times.

Thanks Jeff

Garandman- I used the patch out accelerator last night followed by the foam cleaner. Did a good job with the copper. The JB knocked out the carbon in the barrel. Now I'll concentrate on the ring.



Thanks for the replies!
 
At the risk of being condemned as a "nerd" (frequently suffer from far worse) I have attached a link describing the physical properties of carbon.

https://en.wikipedia.org/wiki/Carbon

Reading this and getting past the high level academic stuff I see that carbon cannot be dissolved by common acids (this has been my experience) that would do a number on your rifle barrel. So, if the black stuff goes away after a soak in bore cleaning solvent this would indicate the black stuff is not carbon or at least not entirely carbon. A mechanical attack with some mild abrasive would be probably the best way to remove the black stuff. Other metallic compounds may partially constitute the black stuff like lead and various smokeless powder coatings or burn rate retardant.

Possibly, when the barrel guys at Ruger chambered that rifle they used a reamer that had a non rotating pilot and during the reaming process shallow annular grooves were scratched into the barrel steel at the end of the chamber neck. The black stuff might be covering these grooves/defects. Upon use more black stuff is deposited then removed, like cyclic. Another careful look might provide more info and gentle lapping might polish any rough spots away.

I like Gun-Slick foam then loose patch then nylon brush job with 5-30W HD synthetic motor oil then loose patch(s). Note the "Patch Out" can - "Wet a nylon brush ….." - probably contains a copper dissolving chemical. For real stubborn fouling I use J-B, this might contain diatomaceous earth, made from the bodies of tiny dead sea creatures.

garandman's stuff is very similar to what I use, except my motor oil brush flushing.

Edit - the JB stuff contains Garnet - a sharp edged mineral commonly used as an abrasive.
 
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@Coonman300

You'll likely never get all that carbon layer out, it's been ran-over to many times and is burned in. Will suggest to definitely get more out, but at some point just stop. Then continue on using the barrel, and doing a better job of not letting it get that built up ever again.

In my experience, that is what many used barrels look like, and what layered carbon does to them over time, when neglected layers are ran-over and over without ever getting truly cleaned out/down to bare metal.
 
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Might want to read this thread, do a search for it, Cleaning solvent opinions on KG1/KG12, Patchout I have been very happy with KG12 and some of their other products.
 
Suggestion: Cut down the size of that first solvent soaked patch. Generally I am opposed to the use of tight patches. For my 6mms I use a .22 piercing jag and 1 3/8" square patches. Once the barrel gets wet the going should get easier. How are you applying the JB? When you have used it, did you keep going until all of the carbon was removed?

For .25 and .26 caliber I like to use the 1 1/8 patches for loose patches. I don't see how one could effectively coat the bore with cleaning compounds using a tight patch. So it's a loose patch of accelerator and a loose patch of wipe-out. Tight patch is usually 1 3/4 IIRC. The first tight patch has some hexane or 90% alcohol on it followed by a dry tight patch. The first couple treatments usually come out black and copper after that.
 
Last edited:
@Coonman300

You'll likely never get all that carbon layer out, it's been ran-over to many times and is burned in. Will suggest to definitely get more out, but at some point just stop. Then continue on using the barrel, and doing a better job of not letting it get that built up ever again.

In my experience, that is what many used barrels look like, and what layered carbon does to them over time, when neglected layers are ran-over and over without ever getting truly cleaned out/down to bare metal.
This is of some interest to me - I have some old barrels that appear to be coated with black stuff inside. I might section portions of a barrel to check out what the ironed in black stuff is and hopefully what caused it.
 
Good thought - No - never shot any moly coated bullets, 6mm AI, steady diet of 105's & H1000, 8 twist, 4 L&G. The lands are dark gray, the grooves are black, the bottom corner of the land/groove is mostly bare stainless but very narrow. Looks sort of like the results of some chemical reaction with the stainless steel instead of a coating. This is a takeoff 6mm AI barrel having about 2,880 rounds through it over 6 years. Except for the worn out throat this barrel appears to be mirror bright inside. No signs of copper fouling.
 
Did you ever shoot moly in it? Itll stay behind in an otherwise clean barrel like that

Would you advise for or against using moly coated bullets exclusively in a new barrel?

Would any here with fouled barrels benefit from doing what Merrill Martin described as fire lapping? Coating lead bullets with polishing grit and firing them in low velocity loads.
 
Would you advise for or against using moly coated bullets exclusively in a new barrel?

Would any here with fouled barrels benefit from doing what Merrill Martin described as fire lapping? Coating lead bullets with polishing grit and firing them in low velocity loads.
No moly and let the barrel mfr lap the barrel right
 
Would you advise for or against using moly coated bullets exclusively in a new barrel?

Would any here with fouled barrels benefit from doing what Merrill Martin described as fire lapping? Coating lead bullets with polishing grit and firing them in low velocity loads.
Against. I would follow the practices recommended by the group of gunsmiths who serve the shooters who compete in sanctioned competition benchrest. None of these that I am aware of recommend this sort of thing. There has been some smoothing of reamer marks in the area of the leade angle during the chambering process to speed breakin, but none that I know of do what you described. Merrill was very involved in cast bullet shooting, and low pressure lead alone will not smooth out roughness like typical jacketed bullet loads.
 
View attachment 1144861 View attachment 1144861 I have my fathers older Ruger 6mm Rem that is giving me fits. The barrel had been neglected for years without being properly cleaned until recently. Accuracy was poor and I was not able to get the proper sized patch down the barrel without using a mallet...got stuck halfway down! Went thru some rigorous cleanings with different solvents without much success. Was advised to use JB Bore paste and it made a world of difference and regained accuracy. My problem is it fouls up so bad after a few shots you can't get the regular patch in the barrel. I did the JB cleaning again and the patch goes thru without a problem. I just got one of the teslong Bore scopes and checked out the barrel after cleaning and saw there was still a lot of carbon fouling in the first few inches of the barrel. Hit it one more time with JB and it looks much better. My question is this- is it possible that there was so much carbon build up that even after many cleanings and 2 JB treatments a barrel would get so fouled in 10-12 shots the patch can't get down it? The patch literally gets jammed at the end of my Bore guide. Would something else be causing it? I took a picture of a black ring that is at the end of chamber in front of the rifling. Is this a carbon ring? Sorry for such a long post but this is new to me. I'm a hunter and shoot for fun and just getting into the more precision reloading and barrel cleaning. Many thanks.

I'd say that your barrel is about done by the looks of it, anyway You might give 0000 steel wool wrapped around a mop
coated with IOSO bore paste to remove the ring. I don't think the ring is giving you hard patch installation but is due to all the fowling build up after the ring.
 

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