Scoring in new chamber , leaving marks on brass .

[Boomhauer_lives]

hi everyone first time poster , i got a new barrel for my first bolt gun . Got the addiction and have been heavily chasing accuracy . So when this barrel arrived it took me a bit to get it installed and i checked it out with a bore scope , i saw chatter on the neck , but i also saw 2 grooves on the side wall about 1/4 an inch down from the neck around the circumference . I went and put some rounds through it and it shot very well . I was getting sub half moa with my reloads with no load development . But i noticed it was leaving a ring on the brass in the spot of the grooves that was deep enough to feel with your fingernail .

I reached out to the smith who made the barrel and asked if i should try and polish it up or what and he said i could try or if i felt it needed replacement he would be happy to swap it out as well . I told him i would try again after giving it a light touch up .

So i hit the chamber with some red then green scotch brite on a wooden dowel . The grooves looked a but better and the sharp edges had been dulled but they were still there . The chatter on the neck was basically gone .

So today i took it out and shot again it shot incredible , one half moa and 2 sub quarter moa groups . The markings on the brass were still there though only part way around the brass not a full circle . I just purchased a bunch of new lapua brass i dont want to screw up . But i also do not want to send back this barrel that shoots so well .

The way i see it i have three options

1- polish it further ( pros and cons )

2- ignore it ( will this lead to decreased brass life , inconsistency with ammo after a few reloads ? )

3- send it back

Anyone especially smiths or barrel makers that might have any advice i would appriciate it .

 

[rustyinbend]

I have a chamber-honing brush from Brush Research for every one of my precision rifles, and a jug of Flex-Hone oil. When I get a new rifle barrel, I always hone the chamber to avoid exactly the problem you're describing. I also do an abbreviated honing every 500 rounds or so ... just because I can. I can't say it's "always" because of this, but I can tell you that I've never scarred a piece of brass with a chamber imperfection ... ever.

 

[Boomhauer_lives]

I have a chamber-honing brush from Brush Research for every one of my precision rifles, and a jug of Flex-Hone oil. When I get a new rifle barrel, I always hone the chamber to avoid exactly the problem you're describing. I also do an abbreviated honing every 500 rounds or so ... just because I can. I can't say it's "always" because of this, but I can tell you that I've never scarred a piece of brass with a chamber imperfection ... ever.

View attachment 8194828

So no real concern about dimensionally changing the chamber ? I went at it with some scotch brite for what felt like a pretty long time to get the marks out

 

[kthomas]

I'm going to tag in @Frank Green and @LongRifles Inc.

 

[Chris1972]

I had this same situation and had it corrected by the manufacturer. Then again my rifle didn’t shoot like yours is.

It’s easy to see the before and after in this picture.

Fix it, you’ll never be happy. That’s my two cents.

 

[Bugholes]

Pretty please, with sugar on top, dont do this to one of my chambered barrels

 

[45-90]

Send it back...to rechamber it...the real fix.

 

[Shifty6BR]

Sounds like the smith is more than willing to help you out via replacement or perhaps other means as you stated.

That's a solid response, personally I would go this route.

 

[Maxduty]

I'm gonna say send it back. It's only going to take a little work to fix and you won't have to worry about brass life. Safety third you know.

 

[rustyinbend]

So no real concern about dimensionally changing the chamber ? I went at it with some scotch brite for what felt like a pretty long time to get the marks out

Not if you follow the directions, don't over-hone, and use lots of honing oil. Now all bets are off if you speed-drill, hone for 20 minutes, and don't use enough oil. But a 30-second hone with the right tool, at the right drill speed, using lots of oil ... has been all good for me.

 

[Frank Green]

I have a chamber-honing brush from Brush Research for every one of my precision rifles, and a jug of Flex-Hone oil. When I get a new rifle barrel, I always hone the chamber to avoid exactly the problem you're describing. I also do an abbreviated honing every 500 rounds or so ... just because I can. I can't say it's "always" because of this, but I can tell you that I've never scarred a piece of brass with a chamber imperfection ... ever.

View attachment 8194828

I'm not picking on ya but have to give you a funny!

The Flex Hones we called them "Monkey Balls"

I know places that use them in polishing chambers.

 

[rustyinbend]

I'm not picking on ya but have to give you a funny!

The Flex Hones we called them "Monkey Balls"

I know places that use them in polishing chambers.

Monkey balls ... that's a good one.
I thought they were pretty odd-looking, but I had less-than-perfect chamber on a new barrel, and a buddy suggested it. Worked great, been a fan-boy ever since. (Or maybe that's a "fan-chimp".)

 

[Frank Green]

hi everyone first time poster , i got a new barrel for my first bolt gun . Got the addiction and have been heavily chasing accuracy . So when this barrel arrived it took me a bit to get it installed and i checked it out with a bore scope , i saw chatter on the neck , but i also saw 2 grooves on the side wall about 1/4 an inch down from the neck around the circumference . I went and put some rounds through it and it shot very well . I was getting sub half moa with my reloads with no load development . But i noticed it was leaving a ring on the brass in the spot of the grooves that was deep enough to feel with your fingernail .

I reached out to the smith who made the barrel and asked if i should try and polish it up or what and he said i could try or if i felt it needed replacement he would be happy to swap it out as well . I told him i would try again after giving it a light touch up .

So i hit the chamber with some red then green scotch brite on a wooden dowel . The grooves looked a but better and the sharp edges had been dulled but they were still there . The chatter on the neck was basically gone .

So today i took it out and shot again it shot incredible , one half moa and 2 sub quarter moa groups . The markings on the brass were still there though only part way around the brass not a full circle . I just purchased a bunch of new lapua brass i dont want to screw up . But i also do not want to send back this barrel that shoots so well .

The way i see it i have three options

1- polish it further ( pros and cons )

2- ignore it ( will this lead to decreased brass life , inconsistency with ammo after a few reloads ? )

3- send it back

Anyone especially smiths or barrel makers that might have any advice i would appriciate it .

Got any pic's?

My opinion... I don't think it will affect brass life at all unless for some reason the gouges are super deep and it's affecting how the brass stretches and resizes etc.... Then it might be a safety issue or affect brass life. If the rings or gouges are not really deep then it's just going to be a cosmetic thing on the brass. When you resize the brass it will to an extent smooth it out. You will probably still see it but won't affect anything. I've seen some pretty rough chambers where the brass came out pretty crappy looking and it never affected anything.

What caused it? Could've been the way the reamer was ground? Could be that the reamer has chambered a lot of barrels and not cutting as nice as it use to. A combination of the reamer, the oil and the way the steel was machining etc...

Pictures would help.

Later, Frank
Bartlein Barrels

 

[LRI]

I was tagged so here goes. :

First, honing, polishing, whatever is intended to improve surface finish. If one is after a dimensional change, it is not how you solve the problem. My interpretation from your post (OP) is that you have inclusions in the chamber. The grooves ("1/4" down from neck") are what caught my attention. Generally speaking, grooves, rings, hoops, etc are caused by chipweld. Basically, a little nub of barrel steel welds itself to the cutting surface of the tool. Because heat is involved, it also hardens. Next, it plows its way around the inner circumference of the chamber and makes a ring. -About like dragging your toe through wet beach sand.

Ignored, the brass will yield under normal chamber pressures and squirt itself into the groove, creating a mechanical lock that will make extraction a nightmare. Attacking it with a sanding roll results in a chamber no longer to print. The body taper is now forever altered. Will it still work? Yes, maybe, or nope. It's very dependent on the parent case. I would imagine a 22-250 being more forgiving than an Ackley-type cartridge because of the radical difference in body taper between the 2 case designs.

In a "fire and forget" scenario where you leave your brass to rot in the earth, I guess it matters nothing so long as it functions and accuracy is not affected. For the handloader, it will likely result in an accelerated depreciation on your brass. I would expect you to notice it when sizing fired cases. The absolute worst situation I can imagine is a ring like this on a nearly straight-walled case that was "polished" in an effort to fix it. Only now, the shoulder diameter is larger than the web. A piece of fresh-sized brass falls in effortlessly, but when it goes bang, it's now stuck. What happens is your chamber is now serving double duty as a sort of backwards sizing die when you attempt extract the case. The only solution I have found for instances like this is to bite the bullet and either set the barrel back (start over) or it gets replaced. I spent a great deal of time and money over a decade ago getting my tool package sorted out so that I don't have to deal with this aggravation anymore.

Hope this helped.

C.

 

[Frank Green]

Still don't see any pics from the OP.

 

[Boomhauer_lives]

Got any pic's?

My opinion... I don't think it will affect brass life at all unless for some reason the gouges are super deep and it's affecting how the brass stretches and resizes etc.... Then it might be a safety issue or affect brass life. If the rings or gouges are not really deep then it's just going to be a cosmetic thing on the brass. When you resize the brass it will to an extent smooth it out. You will probably still see it but won't affect anything. I've seen some pretty rough chambers where the brass came out pretty crappy looking and it never affected anything.

What caused it? Could've been the way the reamer was ground? Could be that the reamer has chambered a lot of barrels and not cutting as nice as it use to. A combination of the reamer, the oil and the way the steel was machining etc...

Pictures would help.

Later, Frank
Bartlein Barrels

The extent of the marking on the brass was enough to catch a fingernail . I polished it lightly then polished it aggressively and it took way too long to get mostly out . I went ahead and sent it back to the manufacturer . I do believe it was just a problem with something during machining .

 

[Boomhauer_lives]

Heres images for those that requested

 

[Mr. F]

My experience as someone who shoots with a scratched chamber 300prc because of a dumb reloading mistake

I think brass life will not be affected unless we are talking a deep deep gouge something over .01-.015" which i dont think that's your case. Bore scopes make stuff look way worse than it really is.

Probably what's gonna happen is brass will smear over the groove and fill it over the few first rounds after each cleaning and over the course of a shooting weekend the marking will be either very faint or not there at all. From the pics im willing to bet if there is some marking on the brass it will be cosmetic.

As far as machining, def not stellar but good on the smith to offer to swap it.

Would i swap it? No, because finding a barrel that shoots quarter MOA effortlessly is generally harder than finding a barrel without any imperfections. That imperfection is not gonna get worse prob will just get better when brass fills. If you re a guy that over thinks this stuff then take the smith up and swap it otherwise run it till is toast.

 

[ScottVA]

Polishing or honing a chamber to a mirror finish reduces the case's ability to grip the chamber walls when fired and thus, generates increased bolt thrust in a bolt gun. Gouges, spurs, reamer etching in chambers that leaves substantial markings on brass should be sent back to manufacturer/builder.

 

[45-90]

Those are

Heres images for those that requested View attachment 8198001View attachment 8198002

Those are longitudinal lines, most likely caused by a dull reamer, chipped cutting edge, too long without reamer withdrawal and cleaning the chips off, not enough or wrong cutting fluid.
The spindle was off when the reamer was pulled out causing longitudinal gouging lines and the chip build up gouged passed the finish diameter of the chamber close to being completed.
No gunsmith should allow that chamber out of the shop. It's an easy fix for a real gunsmith and you will have a perfect chamber... rechambering a barrel to clean up this bad chambering job, will not affect accuracy, as the barrel itself contains the accuracy, not the chamber...as you can see... cause it likes the bullet that is being put through it. Most chambers have .0002 TIR some to .0005 and still be accurate, the most critical part of the chamber...the angles, the form, and roughness of the chamber have little to do with accuracy, but function. Have it rechambered...correctly...unless you got a big discount, you paid full price for unacceptable work. Not much left to discuss.

 

[357Max]

Heres images for those that requested View attachment 8198001View attachment 8198002

Those pics after the polishing?

Monkey balls, hadn't heard that in a long time. I always called those dingle berry hones.
The most I've ever done was to just break the sharp edge into the chamber at the breach followed by a few strokes with a Sunnen brush. They will not change dimensions by design.

Sometimes shit gets out without a proper inspection. This one got replaced.

 

[Stephen Bachiler]

FWIW- I had somethings raised in my chamber that was damaging my brass. I went the honing brush route and it took care of it quickly. Brass looks great...rifle shoots great

 

[Kohl604]

DO NOT, I repeat DO NOT stick a mini dingleball hone in your chamber. That hack method is solely reserved for $5.00 small block chevy rebuilds.
Send it back to the smith, if the problem is not resolved send it to a competent smith. There should be no burrs/chatter in your chamber period.

 

[Stephen Bachiler]

DO NOT, I repeat DO NOT stick a mini dingleball hone in your chamber. That hack method is solely reserved for $5.00 small block chevy rebuilds.
Send it back to the smith, if the problem is not resolved send it to a competent smith. There should be no burrs/chatter in your chamber period.

I already did. It solved the problem and the rifle is not worse for the wear. It took 20 seconds. The rifle is still 1/2 MOA.

What's the problem?

Sure...if you're an incompetent don't do it..but if you are thoughtful and patient/careful...I see nonissue with it