Carbon ring?

[The Oregonian]

I realize these aren't the best pics and that it would be better if I had a 90* Hawkeye attachment, but I don't have a Hawkeye nor do I know someone who does.

Given all of that, does this look like a carbon ring right at the end of the chamber where it transitions into freebore? It is very thin and may just be firecracking. I worked it over with simichrome and didn't really make a dent in it at all, but I have Iosso and the brownells cleanings pellets on the way.

I'm not sure if this is a carbon ring and more elbow grease is required or if this is just normal wear / fire cracking from shooting and i shouldn't hit it with Iosso. Gun is a 280AI with about 300 rounds down the tube. I clean regularly but am wondering if using a Lucas bore guide would extend past this area and prevent the patches from contacting it during cleaning. I haven't had the bore scope long and am no expert at what I am seeing.

Thx

 

[Wedgy]

It is fairly hard to see without the 90 degree view but it will be after the end of the brass and before the rifling, picture shows clean chamber until the brass ends and the carbon starts. Usually you will show sudden pressure or significant loss of accuracy when you get a hard ring. Has to be removed with an abrasive such as JB or Isso. Don't sweat the fire cracking, I've seen barrels with chunks missing out of the throat that still shot great.

 

[The Oregonian]

Thanks. The only area I am concerned with is the black area right behind what shows up as really bright where the chamber ends. Is that firecracking or is that likely a carbon ring?

Here is a video which might show this better.



What makes me think it could be a carbon ring is the difference in velocities I was getting over the last few days...like a ~60fps increase. Dates, temps, etc are on each chart. Unless noted, all seating depths are .020 off the lands.

 

[Wedgy]

I can't tell from the video but get a jag and a patch with some JB or Isso and a little Kroil or similar and short stroke the throat, if you get some black it's carbon.

 

[The Oregonian]

I can't tell from the video but get a jag and a patch with some JB or Isso and a little Kroil or similar and short stroke the throat, if you get some black it's carbon.

Thanks...would that be a common or uncommon place to see a carbon ring?

I have the Brownells pellets and Iosso on the way to be able to hit that area by twisting the pellets with a bore rod.

 

[hunterdan]

I have the Brownells pellets and Iosso on the way to be able to hit that area by twisting the pellets with a bore rod.[/QUOTE]

The pellets work great for short stroking the first part of the bore for Carbon, But I have found a oversize Iosso brush are Brass brush with a piece of cleaning patch wrapped around the top part of brush with Iosso are JB paste and twisting this in the throat area will clean it up pretty fast.

 

[Tensilon]

Oregonian...I would say that carbon issues in the throat area happen quite a bit especially if one is shooting an overbore cartridge. The throat area is also one area that is more difficult to get clean because it, generally, takes most of the abuse that is being created by the launch of the bullet i.e. higher pressures and higher temperatures in relation to the rest of the barrel. From my understanding, if this area is left to accumulate it will further accelerate the demise of the barrel as the rough and uneven surface will gather more detritus over time. I do have a borescope and I have seen this before as Wedgy has described. Although I have pellets and and the various bore polishes, what I use is a somewhat undersized older bore brush be it copper or synthetic and a small rectangular patch of scotch brite brown (6444 fine) or maroon (7447 very fine). I cut a small rectangle that can be rolled around the old brush and tie it on to the brush with thread in a circular fashion. It should fit somewhat tight but not so tight that you have to beat it into the bore, lol. I then use JB or Iosso spread around the setup to concentrate on polishing the throat area. Some might disagree with this practice but in essence keeping a clean or "polished" throat will keep the barrel from degrading quicker in this area. What you are doing is removing the carbon and fouling. Your intent is not to try and remove metal. This is not something that I do often but if a throat is in need of serious cleaning and looks like Wedgy's example, I would not hesitate to clean it up like this. It works well and a smooth throat will no doubt prolong the life of your barrel.
Now, if you believe me to be FOS... I would recommend you should check out Nathan Foster's excellent site https://www.ballisticstudies.com/. I would think that many other's on this site can confirm that the information proffered by Nathan is of immense value. I have used his advice and methods many times to address issues that I have run into putting together my own rifles for long range.
Best of luck in your endeavors with your rifle,
Tens

 

[Dosh]

I can't tell from the video but get a jag and a patch with some JB or Isso and a little Kroil or similar and short stroke the throat, if you get some black it's carbon.

IOSSO bore cream will show black even in a clean barrel, but it will get that carbon ring quickly. Don't forget the bore guide. Good luck

 

[Barrelnut]

You need a Lyman bore scope. They have a 90 degree view. Carbon rings show up really well with them. They are useful and inexpensive.
https://www.amazon.com/dp/B00URUE84W/?tag=lrhmag19-20

 

[brguide]

if its at the edge (neck to freebore transition) its most likely gas erosion, thats what i am seeing. Gas erosion looks like someone used a pick o=all the way around that edge. You could have barrel set back but in reality you will not stop it.

 

[The Oregonian]

You need a Lyman bore scope. They have a 90 degree view. Carbon rings show up really well with them. They are useful and inexpensive.
https://www.amazon.com/dp/B00URUE84W/?tag=lrhmag19-20

Ordered....will post pics when I get it and look at that area.

 

[Wedgy]

Ordered....will post pics when I get it and look at that area.

It's totally worth $200 to not be wondering if it is a carbon ring or not...eliminate that then on to the next thing....then the next. LOL
Keep us posted

 

[The Oregonian]

You need a Lyman bore scope. They have a 90 degree view. Carbon rings show up really well with them. They are useful and inexpensive.
https://www.amazon.com/dp/B00URUE84W/?tag=lrhmag19-20

It's totally worth $200 to not be wondering if it is a carbon ring or not...eliminate that then on to the next thing....then the next. LOL
Keep us posted

The beauty of living near an Amazon warehouse...free one day shipping. Looks to me to be squeaky clean, which makes sense as I went to town on the area. Doesn't mean there wasn't something there a few days ago.

Now to go shoot and see where velocities are, though I am sure I need to foul the barrel quite a bit.

 

[Frog4aday]

Great pics. That's a nice bore scope. Dang it. Now there's something else I want to have. This gun thing really adds up. Glad you were able to know for certain what was going on with your gun. Thanks for the follow-up post.