Dusty Stevens
Shiner
If its a ring around the base all the way around its carbon. Using the proper fitting bronze brush after you scrub it with jb will alleviate it in the future
Need pressure schooling !
- Thread starter SavageMark
- Start date
Gotcha ! Thx much .
So the carbon ring is adding pressure similar to extreme neck tension ?
You would think they would check it with pin gages before it leaves the factory !
The first thing that goes on a chamber reamer is the throat. When the throat starts to go on the reamer it will cut undersize and can leave burrs in the throat as well.
Also ask for a copy of the reamer print that was used to chamber the barrel. Check what the throat diameter is suppose to be. Let’s say it’s specd at .2433”.
Get a good mic and mic your lot of bullets. If your bullets are fat and are at .2433” your size on size and or going back to the reamer if the throat is going on the reamer it could’ve cut undersize.
All that being said nobody brought up....what is the bore and groove size of the barrel you have no the gun? If the bore is tight/undersize that will drive up pressures as well. If that’s the case you will have to back off the loads more than you think. A tight groove is even worse than a tight bore. A .0005” tight on the groove and bore can and will drive up pressures about 10k psi.
You need to know the bore and groove size to the 4th decimal place. Like .2372” x .2433”. Just saying it’s a .237 and .243 isn’t going to tell you anything.
A brush and a paste/abrasive cleaner not used properly will damage barrels. So be careful. There are times I’ll say you have to resort to something like this but if your not careful damage to the bore will result. Say what you want....I’ve got enough pictures of barrels that have been damage by poor cleaning habits.
Also the hard carbon deposits laying in the bristles of the brush can scratch the bore of the barrel as well. So regularly make sure you clean the brush off of any dirt looking particles.
All being said if you have problems it wouldn’t hurt to call the barrel maker and talk to them.
Later, Frank
Bartlein Barrels
Also ask for a copy of the reamer print that was used to chamber the barrel. Check what the throat diameter is suppose to be. Let’s say it’s specd at .2433”.
Get a good mic and mic your lot of bullets. If your bullets are fat and are at .2433” your size on size and or going back to the reamer if the throat is going on the reamer it could’ve cut undersize.
All that being said nobody brought up....what is the bore and groove size of the barrel you have no the gun? If the bore is tight/undersize that will drive up pressures as well. If that’s the case you will have to back off the loads more than you think. A tight groove is even worse than a tight bore. A .0005” tight on the groove and bore can and will drive up pressures about 10k psi.
You need to know the bore and groove size to the 4th decimal place. Like .2372” x .2433”. Just saying it’s a .237 and .243 isn’t going to tell you anything.
A brush and a paste/abrasive cleaner not used properly will damage barrels. So be careful. There are times I’ll say you have to resort to something like this but if your not careful damage to the bore will result. Say what you want....I’ve got enough pictures of barrels that have been damage by poor cleaning habits.
Also the hard carbon deposits laying in the bristles of the brush can scratch the bore of the barrel as well. So regularly make sure you clean the brush off of any dirt looking particles.
All being said if you have problems it wouldn’t hurt to call the barrel maker and talk to them.
Later, Frank
Bartlein Barrels
Just measured a few bullets and they come out at .2432. I’ve got a different bullet at home that I’ll check tomorrow at work . I have gage pins but they are in .0005 increments . I’ll try and figure out bore diameter but not sure how to do groove dia.
Thx
Mark
Unless you have proper bore/measuring equipment getting a correct/good reading on the groove size is going to be hard.
If you have a good set of pin gauges you can get the bore size with in a .0001". Be careful pushing the pins into the bore that you don't scratch it (bore) and or get a pin stuck in it.
I would also avoid trying to push a pin thru the whole length of the barrel. Any small lint or dirt particle or even just from the suction you can get the pin stuck. Then you can be screwed.
Just pin the muzzle end. Start small on the pin size and carefully work your way up.
I've seen plenty of primers with the burr/built up crater like the ones in your very first post. Besides pressure that can be from a oversize firing pin hole in the bolt and or a under size firing pin tip or a combination of both. I've got 3 Savage 112 J series guns (mid 70's production) single shots. Last year I rebuilt on in .223 Rem. for my son and the other I changed it from a .243win. to a 6BRA. Both leave the craters on the primers and there are no pressures issues/hard bolt lifts etc....I've seen it on other rifles and not just a Savage.
Greg at Gre Tan Rifles might be able to bush the firing pin/bolt for you. I've never asked him about doing Savage bolt heads but don't know why it couldn't be done off hand.
Here is a pic. of my 6BRA brass/primers.
Greg at Gre Tan Rifles might be able to bush the firing pin/bolt for you. I've never asked him about doing Savage bolt heads but don't know why it couldn't be done off hand.
Here is a pic. of my 6BRA brass/primers.
Attachments
In regards to a brush not possibly causing bore damage....here are a few pics and this is why I say be careful of what you do and how you do.
First two pics (sorry for the quality) and I circled to help point out what your suppose to be looking at. This is from spinning a brush on a rod hooked up to a cordless drill on high speed. Only made 4 passes thru the bore with the drill, exited the muzzle once and pulled it back thru and out the breech end while still spinning the drill on high. Muzzles crown started to get dinged up with only one exit of the brush and you can start to see the scratches showing up in the bore. The edges of the lands you could start to see where the scratches went across the tops of the lands where starting to go thru the edges. The only thing that helped save the edge of the lands from real abuse was because this had 5R style rifling. If this was conventional/standard type rifling the hard edge of the lands would've looked like someone took a ball peen hammer to them.
Last picture is from using a brush and bore paste. This guy polished out a full .002" off of the lands (the bore) and a .0015" out of the grooves. Barrel only has 800 rounds on it. Started having accuracy issues at 100 rounds!
First two pics (sorry for the quality) and I circled to help point out what your suppose to be looking at. This is from spinning a brush on a rod hooked up to a cordless drill on high speed. Only made 4 passes thru the bore with the drill, exited the muzzle once and pulled it back thru and out the breech end while still spinning the drill on high. Muzzles crown started to get dinged up with only one exit of the brush and you can start to see the scratches showing up in the bore. The edges of the lands you could start to see where the scratches went across the tops of the lands where starting to go thru the edges. The only thing that helped save the edge of the lands from real abuse was because this had 5R style rifling. If this was conventional/standard type rifling the hard edge of the lands would've looked like someone took a ball peen hammer to them.
Last picture is from using a brush and bore paste. This guy polished out a full .002" off of the lands (the bore) and a .0015" out of the grooves. Barrel only has 800 rounds on it. Started having accuracy issues at 100 rounds!
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Was the brush and paste damage done using the drill, or by hand?
By hand!
I should of pointed that out but didn't think about it. That's not the only one as well and not just using paste.
Guys using a brush and liquid abrasives have done the same thing. I had one guy wreck/damage 3 barrels in like 6 months and was using a brush and Witch's Brew. Those barrels where 6mm and 6.5's. Another guy did a .308win. barrel about 6 months later.
Also spinning the brush on a rod in those first two pictures. No abrasive was used. The bore was wet with Boretech Eliminator solvent first and then the brush and rod/drill treatment was done to it.
To add to this ...... a reamer that cuts .0001" undersize and if the bullet was size on size to begin with...that .0001" tighter on the throat can drive up pressure 4-6k psi. Doesn't sound like much but when the ammo is already running at max. pressure that extra 4-6k can make a difference.
Last year we ran into a instance on pressure test barrels. The caliber was .30cal. and the throat diameter was spec'd at .3090" and ref. ammo came in at max. diameter on the bullet which was spec'd a .3090" (I'd like to meet the guy that wrote that spec. up and have a conversation). Any way the reamer cut the throat at .3089" and it bumped the pressures 4-6k on the ammunition as well as it bumped the velocities. We recut the chambers with a new/correct reamer and everything came into spec.
Im waiting to hear back from Shilen . In the mean time I’ve got a bottle of C4 coming tomorrow . Going to let throat soak in it overnight and see if it’s actually a carbon ring .
CaptainMal
Silver $$ Contributor
You really need a bore scope with BR-based cartridges. It is the most miserable carbon-fouling combination I have ever experienced. Also think it is impossible NOT to foul the bore with carbon from Varget, H4895, Rel 15, Rel 16 and maybe other powders. Once hard I have found NO solvents that work.
Sure I do use something the helps but cannot tell you what the stuff is for carbon. It is not made for rifles and can do serious damage to blueing and even metal. Yet alone, it is not the answer. Sometimes that brush with IOSSO or JB Bore Paste is a major help. Then again - serious messes may need that darn brush spinning on a drill for the first 4 " or so. By then the barrel is probably on its' way out anyhow.
You need a bore scope to see if that is the issue. If it is, the image will not be hard to find. Black streaks or layers will be filling the grooves and ushered on top of the lands. Look. You will easily see with a bore scope. If no bore scope there is no reasonable way to actually see the problem.
Sure I do use something the helps but cannot tell you what the stuff is for carbon. It is not made for rifles and can do serious damage to blueing and even metal. Yet alone, it is not the answer. Sometimes that brush with IOSSO or JB Bore Paste is a major help. Then again - serious messes may need that darn brush spinning on a drill for the first 4 " or so. By then the barrel is probably on its' way out anyhow.
You need a bore scope to see if that is the issue. If it is, the image will not be hard to find. Black streaks or layers will be filling the grooves and ushered on top of the lands. Look. You will easily see with a bore scope. If no bore scope there is no reasonable way to actually see the problem.
Can’t afford a scope right now . Also can’t believe I can’t find any pics online similar to my issue . Don’t know if it’s a burr or carbon ring or undersize throat ! This sucks ! Lol
Borrow one...Captain speaks the truth..
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