Is it a carbon ring?

rtockstein

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Just broke down and got a borescope. This is a picture of the end of the chamber neck area. Chamber is bottom right, leade is top left. Is the light grey colored spot a carbon ring?
 

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LaHunter

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How many rounds fired since you last cleaned? To me, it looks like it could be a carbon ring. That is the location that one would form.

When you last cleaned, what was you procedure and did you use bronze bore brush? Many time those carbon rings can take a good bit of effort to get them out
 
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rtockstein

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Good to know! Thanks.

I was actually in the middle of cleaning it when I took that picture. I had it soaking with accelerator and tactical advantage. I wiped the bore out and then inspected. I will have to get on that with a brush and or some other abrasive.
 

LaHunter

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Good to know! Thanks.

I was actually in the middle of cleaning it when I took that picture. I had it soaking with accelerator and tactical advantage. I wiped the bore out and then inspected. I will have to get on that with a brush and or some other abrasive.
Boretech makes some good products. You will want to use something made for carbon fouling. Be careful with abrasive products. You can do more harm than good. Also, some good quality bronze brushes will likely be needed
 

Brendan

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Get some Boretech C4 Carbon cleaner, Iosso or JB Bore Paste. Soak with the C4, then go after it with the iosso on a patch over a bore brush short stroking that area. Clean it out - re-check with the Borescope.
 

deadwolf

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Following, as I’ve dealt with this issue once and welcome the further education.


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kharb22

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Here is a link to Straightjacket armory about cleaning and barrel break in. He talks about the process he uses to remove carbon from his barrels

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rtockstein

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Here's some pics after a few strokes of JBs and PB blaster penetrating oil (don't have any kroil). Looks better, but maybe a tiny bit left. I'm good with it!

This is after 560 rounds and several pounds of staball (super dirty powder)
 

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Wapiti1

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Out of curiosity, why did you care if there was a carbon ring or not? Did you see your groups go to hell, or velocity swings?

All rifles develop one and it matters on very few. Typically, you only see issues on chambers with tight neck tolerances.

Jeremy
 
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rtockstein

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Out of curiosity, why did you care if there was a carbon ring or not? Did you see your groups go to hell, or velocity swings?

All rifles develop one and it matters on very few. Typically, you only see issues on chambers with tight neck tolerances.

Jeremy

Really just curiosity. I shot 275 rounds of really dirty burning powder without putting a patch through the bore and was curious if there was one there after cleaning. I don't think it will drastically change my groups. I just wanted to see how removing it will affect them.

Also, I just got this borescope, so I just want to learn about what I'm seeing in the bore.
 

Wapiti1

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Ahh a new toy. I love new toys. Just wanted to see if there was a problem you were chasing that we could help with.

Jeremy
 
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rtockstein

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Ahh a new toy. I love new toys. Just wanted to see if there was a problem you were chasing that we could help with.

Jeremy
I think the part that made me really curious about a carbon ring the in Tikka was that I had used a couple different methods to figure out my BTO for touching the lands right after I finished breaking in the barrel when new. I've read that the distance to the lands tend to increase by 0.004 to 0.007 every 100 rounds fired. I just recently bought hornadys coal measuring tool to make it easier to check on my distance to lands. When I measured it with the bullet I'd been using for 500 rounds, I found that the distance was way shorter than I thought. So either I had measured incorrectly when the gun was new and I had been jamming into the lands this whole time, or the lands distance hasn't increased hardly at all, or I had a carbon ring starting to form near the lands. So I wanted to see if there was one in there.

I rechecked my distance to lands last night, and it was the same. So either I measured it wrong a long time ago or my lands are at about the same distance.
 

LaHunter

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I think the part that made me really curious about a carbon ring the in Tikka was that I had used a couple different methods to figure out my BTO for touching the lands right after I finished breaking in the barrel when new. I've read that the distance to the lands tend to increase by 0.004 to 0.007 every 100 rounds fired. I just recently bought hornadys coal measuring tool to make it easier to check on my distance to lands. When I measured it with the bullet I'd been using for 500 rounds, I found that the distance was way shorter than I thought. So either I had measured incorrectly when the gun was new and I had been jamming into the lands this whole time, or the lands distance hasn't increased hardly at all, or I had a carbon ring starting to form near the lands. So I wanted to see if there was one in there.

I rechecked my distance to lands last night, and it was the same. So either I measured it wrong a long time ago or my lands are at about the same distance.
It is really easy to get inaccurate measurements when measuring the distance to the lands. Most methods rely on 'feel', and you can push the bullet into the lands a few thousandths and not know it.
Check out Alex Wheeler's youtube method for measuring the distance to the lands. Alex's method seems to eliminate most / all potential error. The 'carbon ring' typically forms right where the brass ends, so it typically isn't at the rifling . The carbon ring can reduce the neck area diameter if it gets bad enough, this can increase pressure and hurt accuracy in some rifles.
 
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rtockstein

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Yes I've watched Alex Wheelers method. I'd like to do it that way, but I don't have a punch to remove the roll pin holding my ejector in and don't have a tool to put it back it. I've got my method with the Hornady tool dialed pretty well.
 

deadwolf

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Yes I've watched Alex Wheelers method. I'd like to do it that way, but I don't have a punch to remove the roll pin holding my ejector in and don't have a tool to put it back it. I've got my method with the Hornady tool dialed pretty well.
Unfortunately the hornady coal gauge isn’t accurate, unless you have made your own modified case from a piece of brass fired in your rifles chamber.


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