Need pressure schooling !

[SavageMark]

Judging from the mark on the bullet it looks like you were jamming into the lands which will definitely raise pressures even on the smaller powder charge back off the bullet .020 and see if the problem continues the marks on your primer around the firing pin are normal some people have their bolt bushed to be tighter around the firing pin but it is not necessary also check the neck outer diameter on a fired case add .001 that should be extremely close to the neck diameter of your chamber you should have .003 maybe even .004 clearance From a loaded round you may have a tight neck chamber which would not release the bullet properly also causing higher pressures

Figured I’d try what doesn’t cost first ! Lol . Seated bullet .02 deeper and ring disappeared . So is it a carbon ring or am I in the beginning of the lands ? Im still going to clean the hell out of it but figured I would try this first .

 

[Dusty Stevens]

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

 

[SavageMark]

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

Gotcha ! Thx much .

 

[SavageMark]

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

So the carbon ring is adding pressure similar to extreme neck tension ?

 

[SavageMark]

If all your seated bullets leave a ring all the way around like the one in the picture, your throat may have too small of a diameter for that bullet. You are not even reaching the lands.

You would think they would check it with pin gages before it leaves the factory !

 

[FrankG]

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

 

[SavageMark]

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

Very good Info !

Thank you . Im going to send these pics to Shilen !

 

[SavageMark]

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

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

 

[FrankG]

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.

 

[FrankG]

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.

 

[Jdne5b]

@Grimstod does great work on Savage bolt heads. Fixed my .223 right up.

 

[FrankG]

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!

 

[Drolds72]

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!

Was the brush and paste damage done using the drill, or by hand?

 

[JFrank]

I only use cloth patches around a nylon brush . Is this sufficient ?

I don’t wrap anything around a brush, nylon or bronze.
A good tip also is use a 22 cal jag and round cut 243 patches from pro shot for swabbing

 

[FrankG]

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.

 

[FrankG]

Was the brush and paste damage done using the drill, or by hand?

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.

 

[FrankG]

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

Later, Frank
Bartlein Barrels

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.

 

[JFrank]

Your scaring me Frank

 

[Evan]

The stories Frank could tell... Oh wait, he's telling them! Everybody pay attention and stop concocting new and exciting ways to destroy barrels.

I have to say, the bronze brush and a drill take the cake for poor judgement!

 

[SavageMark]

The stories Frank could tell... Oh wait, he's telling them! Everybody pay attention and stop concocting new and exciting ways to destroy barrels.

I have to say, the bronze brush and a drill take the cake for poor judgement!

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 .