Is the carbon ring

R

Richard

Member
that big of a deal ahead of the case? I have tested a totally clean chamber and also left the carbon ring ahead of the case. I cannot really see any difference. This is with 133 powder. What are you guys seeing?
 
I think that there tends to be some confusion about what a carbon ring is. The powder fouling that can build up at the end of the neck part of the chamber is not a carbon ring, it is just an indication that your cleaning method is not reaching that part of the barrel. Beyond that, if you can clean something out of your barrel with a bronze brush, patches and solvent, it is definitely not hard carbon. Furthermore, over a number of 8 pounders, doing inspections with a bore scope, I have never seen a carbon ring after cleaning caused by shooting 133. There has been some missed powder fouling at the end of the chamber neck. A "real" carbon ring, is typically right at the top of the angled transition between the neck part of the chamber and the freebore, and no amount of brushing with solvent will remove it. For those, I use IOSSO on a nylon brush ( I prefer the Dewey brushes for this application.), applied with some care, only as often as required, and no more. Carbon ring formation varies with the powder, cartridge and barrel. Back in the day I used to wonder why Boyer was using IOSSO on a nylon brush between every match. Later I figured out that it was because he was still using T powder and it did form carbon deposits that a bronze brush and solvent would not remove, something that I never saw shooting 133. One thing that you might consider is that when your cleaning technique leaves powder fouling at the end of the case neck, as long as your trim length keeps your necks short of that location, it should not have any effect. Perhaps this is why Jack Neary trims to 1.490 for a 1.525 chamber (Yes, that is .035 shorter than max.). I can remember when I used to trim really close to max, thinking that minimizing the space at the end of the neck would have some accuracy advantage. I was wrong. It wasn't the first time, and (unfortunately) it won't be the last.
 
Back a couple of decades, Australian TR (=Palma) shooters used Australian military 7.62 NATO ammunition. Because of the extreme specs for the powder by the military, we could end up with quite a bit of inhibitor included to modify burn rate. There rounds left what we called a glazed ring at the throat if correct care wasn't used in cleaning. WD40 was one of the favourites but many of used a 50/50 mix of Penetrine (our proprietary penetrating oil) & Sweets oil, applied first with a couple of pushed through patches then in two or three doses with a bronze brush & left until the next shoot.

It worked both to deglaze & as a copper remover.
 
Richard, I have thought about u and this topic because I know u don't clean that often.

My opinion is this ring can be a problem when you have some cases that grow to the point they get on top of the ring left by shorter cases. Less clearance. As you have seen, I trim often to shoot mid pack.

Mark
 
The Benchrest Community is divided into two groups when it comes to the "carbon ring"

Those that lay in bed at night, unable to fall asleep because they fear it.........and those that could care less.

I'm not loosing any sleep over it.
 
Both conditions will hurt you if not addressed. It doesn't matter if you have .010 or .035 clearance at the end of the chamber, left in there carbon will affect bullet release as migrates back under the neck. In the throat it do you in with increased pressure and affect accuracy due to the less groove diameter and increased heat at that point. ….jim
 
Back a ways I talked to TB about the ring(s). Seems he recognized two rings. The carbon buildup in the bore just ahead of the leade was what he attended to the most. In a 6mm bore, with a 22cal jag, a 1-3/8" wet patch you can feel the buildup if you have any. Work the cleaning rod slowly from about 2-3" ahead of the bore to the chamber neck. As you draw the patch back toward the chamber nevk you may feel an additional tightness. If so, give it a good soaking and scrubbing with a proper fitting bronze brush.

The "ring" buildup at the end of the chamber neck is not going to effect accuracy unless your brass has greatly varying lengths.


.
 
i have seen a carbon ring that became a bullet seating ring.
i have seen accuracy go down hill when cases hit the ring and started to
turn in on the bullet like a crimp.

just depends on how long it is allowed to build up.
and how much room is in front of your case before
the throat.
 
Boyd put me on to the Iosso and nylon brush treatment. I do it every 100 rounds or so, but not too aggressively. I'm shooting LT-32 and my bore-scope shows no signs of carbon....ring or otherwise.

-Lee
www.singleactions.com
 
I believe, it's the liquid and carbon left in the neck area. I use a 22 bore mop. Trimmed down at the tip. Yes, it comes out dirty.
Clean this off with break cleaner.
That little bit of cleaner between the o-ring(on bore guide) and throat area is what causes it. Then you insert a round and it gets wicked around the bullet/case and gets baked in.
A bore mop and patch will not touch it. Most people stick the patch in and it come out clean. And call it good. They didn't git in to the neck/throat area.
It's easy to find this out with a bore scope. That's how I found it. "Hey, What's this puddle in the chamber?".
If you only shoot a couple of hundred rounds in a barrel. It's not a problem.....
 
Carbon Ring

If carbon buildup,in the throat area, gets in the way of accuracy, its surprising that some clever benchrest shooter has not designed a special tool/gadget that
addresses this concern. I remember seeing pictures of a gadget that somebody designed specifically for removal of the carbon ring. Don't remember who the designer was. My thinking is, Get rid of the Carbon ring and you can concentrate on looking for the many other accuracy robbing conditions,real or imagined.:D The fun of Benchrest.



Glenn
 
Chism G said:
If carbon buildup,in the throat area, gets in the way of accuracy, its surprising that some clever benchrest shooter has not designed a special tool/gadget that
addresses this concern. I remember seeing pictures of a gadget that somebody designed specifically for removal of the carbon ring. Don't remember who the designer was. My thinking is, Get rid of the Carbon ring and you can concentrate on looking for the many other accuracy robbing conditions,real or imagined.:D The fun of Benchrest.



Glenn
Click to expand...

Ok, I confess. I periodically unscrew my barrels and, by hand, twirl my reamer against the shoulder to get rid of anything in there. I do this I between set backs.

I especially do it on my 30BR, which I do not clean at matches.

Truth is, I never see anything resembling "carbon" on the reamer. But then since I set barrels back on a regular basis, what ever is supposed to be building up in there doesn't seem to have time to build up.

And since someone will ask, the answer is no. It doesn't dull the reamer.

I am a fanatic about keeping throats fresh to the point of paranoia. A good example, that barrel I just shot 25 X's with at Tomball? I have already taken it off, set it back .020, insuring it will be fresh for our upcoming VFS Match in Huntsville the 28th.
 
jackie schmidt said:
Ok, I confess. I periodically unscrew my barrels and, by hand, twirl my reamer against the shoulder to get rid of anything in there. I do this I between set backs.

I especially do it on my 30BR, which I do not clean at matches.

Truth is, I never see anything resembling "carbon" on the reamer. But then since I set barrels back on a regular basis, what ever is supposed to be building up in there doesn't seem to have time to build up.

And since someone will ask, the answer is no. It doesn't dull the reamer.

I am a fanatic about keeping throats fresh to the point of paranoia. A good example, that barrel I just shot 25 X's with at Tomball? I have already taken it off, set it back .020, insuring it will be fresh for our upcoming VFS Match in Huntsville the 28th.
Click to expand...




25 X's at Tomball Gun Club. that's awesome Jackie. Was it the fresh throat or friendy Demon's? Congrats. Your story is a perfect example of the benefits/ advantages of having the right tools and skills to stay on top of the game.

I shot 22 X's one time with my 6PPC. Didn't even know what a carbon ring was.



Glenn
 
Chism G said:
25 X's at Tomball Gun Club. that's awesome Jackie. Was it the fresh throat or friendy Demon's? Congrats. Your story is a perfect example of the benefits/ advantages of having the right tools and skills to stay on top of the game.

I shot 22 X's one time with my 6PPC. Didn't even know what a carbon ring was.



Glenn
Click to expand...

Yeh, Glenn. Most people would think I am insane for unscrewing a barrel and setting it back after that, but as I said, I am darned near paranoid about fresh throats.

http://benchrest.com/showthread.php?95714-Tomball-Varmint-for-Score-Results
 
jackie schmidt said:
Yeh, Glenn. Most people would think I am insane for unscrewing a barrel and setting it back after that, but as I said, I am darned near paranoid about fresh throats.
Click to expand...

Jackie (or anyone), can you explain the theory behind how/why "fresh throats" affect accuracy? Does a worn throat:

1. let pressure escape, thus, creating inconsistent velocities between shots;
2. create inconsistent marks on the bullet, thus, causing inconsistent flight; or
3. do something else, such as ... ?

In addition to the above question about worn throats, I have the same questions about worn barrels. Can y'all enlighten me, please? :)
 
I am going to speak solely about my 30BR, based on my own experiences in Matches.

I discovered long time ago that seating depth is extremely important when looking for that last little bit of accuracy. Yes, 30's are very forgiving. The load window tends to be pretty wide. Barrels seem to last forever. They are very lenient when it comes to neck tension, seating depth, temperature, humidity, etc.

That is, if you want to settle for 18 X's every time out. What you have there, in reality, is a Rifle with about a .300 aging capability.

Take a good look at those targets. That Rifle is shooting at a .200 or better level. I strive to keep it there.

If you want to keep the Rifle shooting at that level on a consistent basis at matches, it's the little things that count.

And I have found that seating depth is one of those little things that will really tighten the agging capability up in a 30. Consistent seating depth depends on a good throat. In order to keep a good throat, you have to be willing to get creative. As in setting barrels back on a regular basis.

These are just my thoughts on the matter. I shoot a lot of score, and I feel like I do OK. I'm really not that good of a shooter. Even after all of these years, I still make stupid mistakes. I have to depend on my Rifle to be at it's best. I have shot around 10 matches this year, and my 100 yard score average is running between 22 and 23 X's.

You can't do that with a .300 Rifle.
 
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THE DIFFERENCE BETWEEN A FRESHLY MACHINED THROAT AND A SLIGHTLY WORN THROAT....THE EXTRA COUPLE OF X'S

Jackie speaks, i listen.
 
jackie schmidt said:
In order to keep a good throat, you have to be willing to get creative. As in setting barrels back on a regular basis.
Click to expand...

Jackie, do you go through a new-barrel-type break-in procedure after the set backs? If not, do you go through such a procedure with a new barrel? Your thoughts, please.
 
On a new barrel, I still put 5 initial rounds through it, cleaning after every one, then around three 2 shot strings, cleaning after each. But I think it is more out of habit than anything else. I know several top shooters who just screw then on and shoot them. By the time they get it sighted in, it's "broke in".

When I set a barrel back, I just screw it back on, sight it in, and shoot it. No particular protocol at all.
 
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