Carbon in the throat, what to look out for.

[Texas10]

Although I've been cleaning my rifles on a regular basis and verifying with my Teslong borescope camera, I was not cleaning them until completely free of all powder residue, tracking or carbon. Just clean enough (or so I thought) not spotless. Well......

I began to notice chambering issues with some loads that were seated close or into the lands. And although they shot well, it became bothersome. Then when pulling a live round for a called ceasefire, I had trouble pulling the bolt back. So I stopped shooting and returned to my shop.

Upon running the Teslong camera up the chamber I found this:



A carbon buildup in the throat was jamming the bullets, and this is how a pressure spike can happen.

I removed it with a vigorous application of bronze brush and Slip 2000 carbon remover, but thought I'd post this pic because I'd never run across one like it before.

 

[338 dude]

Although I've been cleaning my rifles on a regular basis and verifying with my Teslong borescope camera, I was not cleaning them until completely free of all powder residue, tracking or carbon. Just clean enough (or so I thought) not spotless. Well......

I began to notice chambering issues with some loads that were seated close or into the lands. And although they shot well, it became bothersome. Then when pulling a live round for a called ceasefire, I had trouble pulling the bolt back. So I stopped shooting and returned to my shop.

Upon running the Teslong camera up the chamber I found this:

View attachment 1176200

A carbon buildup in the throat was jamming the bullets, and this is how a pressure spike can happen.

I removed it with a vigorous application of bronze brush and Slip 2000 carbon remover, but thought I'd post this pic because I'd never run across one like it before.

I’ve seen pictures of that before but never with that much copper that was obviously getting very tight

 

[Richard Coody]

Most common way to clean the hard carbon out of the throat is wrap a patch soaked in your favorite carbon remover around a jag (I like the parker hale it is long and holds a patch very well) or an old brush. Coat the patch with losso or jb and short stroke the throat and about 10" up the barrel. Common in my 6br with varget.

 

[D-4297]

Was starting to get a carbon ring developing , and my solution was to soak a patch with C-4 , work it into the start of the bore and remove the jag , leaving the patch in place . Every half hour or so , I'd re-wet the patch , for a couple hours . Then it was brass brush time with a marked rod , in a drill motor for a minute or so , at slow speed . Cleaned up the neck and throat quite nicely , without going into the bore . I don't do brass brushes in my bores . Scratches are scratches .And yup ; Bronze & Brass brushes will scratch stainless steel . Or I wasn't payin attention for thirty-five years in the Aerospace Tool-room .

 

[dgeesaman]

Was starting to get a carbon ring developing , and my solution was to soak a patch with C-4 , work it into the start of the bore and remove the jag , leaving the patch in place . Every half hour or so , I'd re-wet the patch , for a couple hours . Then it was brass brush time with a marked rod , in a drill motor for a minute or so , at slow speed . Cleaned up the neck and throat quite nicely , without going into the bore . I don't do brass brushes in my bores . Scratches are scratches .And yup ; Bronze & Brass brushes will scratch stainless steel . Or I wasn't payin attention for thirty-five years in the Aerospace Tool-room .

They will certainly scratch 300 series stainless, but would they scratch 416 stainless?

 

[centershot]

Before you use Iosso, read what Bartlein Barrels says about using it. After reading it, I threw my tube out.

 

[chop house]

A carbon buildup in the throat was jamming the bullets, and this is how a pressure spike can happen.

a couple years back in the pdog wars i had a 204 that was showing exceptional velocity for the powder charge. this was pre-teslong but i did have a rigid .220 borescope that always frustrated me trying to inspect 20 cal. i also did not have very good 20 cal cleaning tools.

so along comes my teslong and better cleaning tools/techniques.... now i am a couple hundred fps short of those 'phenomonal' velocities... but MUCH SAFER.

 

[JEFFPPC]

Centershot, what do they say? I did not find a reference to Iosso on their website. I have used it with Bartlein barrels with success for quite a few barrels.

 

[Texas10]

By popular demand, I am posting a pic of after a thorough cleaning, which took less than 5 minutes.

 

[Liven The Dream]

JB has been around for years ? A Jag rap a patch and JB and some Bore Cleaner ( Montana Copper Killer) ?
get your stroke going, short in the throat area . Once a year or more ,depends on how much you shoot ?

I am always surprised by the Black patches

 

[Texas10]

Some might find this picture interesting. This is a brand new, never shot X-Caliber 6.5 CM barrel that I seated a 142 SMK bullet in a case and then cut down the bullet right to the ogive. The purpose was to photograph the intersection of the bullet ogive as it touched the lands.

In this photo, the bullet is starting to engage the reamer cut ramps on the lands. If you look carefully at he land at the 9:00 o'clock position, you can just see the top of the ramp in front of the face of the bullet.

Although it's hard to tell, I colored the face of the bullet with a black sharpie, but it shows up quite reflective nonetheless.

 

[JEFFPPC]

JB will do the job but I have found Iosso seems to do it quicker. I use both along with Hoppes9 mixed with Kroil, soaking and an overnight check with Sweets. All the rest is in a box under my loading bench.

 

[sqrlgtr]

Some might find this picture interesting. This is a brand new, never shot X-Caliber 6.5 CM barrel that I seated a 142 SMK bullet in a case and then cut down the bullet right to the ogive. The purpose was to photograph the intersection of the bullet ogive as it touched the lands.

In this photo, the bullet is starting to engage the reamer cut ramps on the lands. If you look carefully at he land at the 9:00 o'clock position, you can just see the top of the ramp in front of the face of the bullet.

Although it's hard to tell, I colored the face of the bullet with a black sharpie, but it shows up quite reflective nonetheless.


View attachment 1176316

Koool

 

[SPQR70AD]

JB has been around for years ? A Jag rap a patch and JB and some Bore Cleaner ( Montana Copper Killer) ?
get your stroke going, short in the throat area . Once a year or more ,depends on how much you shoot ?

I am always surprised by the Black patches

if you use a patch and jag wouldn't the patch come off when you pull the rod back?

 

[jonbearman]

I let an AR-15 bolt soak over night in slip 2000 to remove excessive carbon and it didn't touch it even with scrubbing. How did you get it to work?

 

[Liven The Dream]

if you use a patch and jag wouldn't the patch come off when you pull the rod back?

It is a rap around Jag ! Made to be used in that manor .
I sure there must be a YouTube for show and tell ?

 

[butchlambert]

Was starting to get a carbon ring developing , and my solution was to soak a patch with C-4 , work it into the start of the bore and remove the jag , leaving the patch in place . Every half hour or so , I'd re-wet the patch , for a couple hours . Then it was brass brush time with a marked rod , in a drill motor for a minute or so , at slow speed . Cleaned up the neck and throat quite nicely , without going into the bore . I don't do brass brushes in my bores . Scratches are scratches .And yup ; Bronze & Brass brushes will scratch stainless steel . Or I wasn't payin attention for thirty-five years in the Aerospace Tool-room .

Maybe you weren't working with 416 SS in your shop.

 

[BDman]

With my first 6.5 CM, I was warned about the carbon ring from a BR friend of mine. So, I started looking for one (with borescope) every 40-50 rounds and finally saw what I thought was the start of one at 78 rounds. My friend confirmed it. That one required about a 2 hour soak with KG1 and about 10 turns with an AR type chamber cleaning rod and bronze brush. Another shooting friend of mine had a long baked on ring that was sticking bullets. Using the same method, it took doing the same procedure three times with a few more twists of the brush. With the borescope you could see it gradually diminishing. I've learned to keep an eye on it and stay ahead of it by cleaning at the first indication. Just my .02.

 

[centershot]

Centershot, what do they say? I did not find a reference to Iosso on their website. I have used it with Bartlein barrels with success for quite a few barrels.

cleaning part of our website for information on cleaning. We do not recommend things like Iosso bore paste. Why? There is no way to be sure you have removed it 100% from the barrel from cleaning. Some shooters who have used it clean their barrel have found afterwards the barrel all of a sudden had fouling issues. We will not warranty any barrel cleaned with Iosso bore paste type cleaners. We feel the paste cleaners get imbedded into the bore and not properly cleaned out. So the next rounds fired thru the barrel and if there is any residual paste left over it will damage the bore of the barrel. If you want to use a paste type cleaner we recommend Rem. bore cleaner (it is called 40x cleaner now and in the past it use to be Gold Medallion) or use JB Borecompound (not the JB bore brite).

 

[butchlambert]

cleaning part of our website for information on cleaning. We do not recommend things like Iosso bore paste. Why? There is no way to be sure you have removed it 100% from the barrel from cleaning. Some shooters who have used it clean their barrel have found afterwards the barrel all of a sudden had fouling issues. We will not warranty any barrel cleaned with Iosso bore paste type cleaners. We feel the paste cleaners get imbedded into the bore and not properly cleaned out. So the next rounds fired thru the barrel and if there is any residual paste left over it will damage the bore of the barrel. If you want to use a paste type cleaner we recommend Rem. bore cleaner (it is called 40x cleaner now and in the past it use to be Gold Medallion) or use JB Borecompound (not the JB bore brite).

You are with Bartlein?