Brian Pfleuger
Moderator Emeritus
You sure those scratches aren't being caused by feeding/magazine?
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Polishing rifle chamber
- Thread starter yggorf
- Start date
HiBC polish like I have describe have been taught at TSJC for years
A " t " handled polishing stick with a paper roll on it.
Well I can't use the common name the instructor called them as it was a course word.
This is to smooth the chamber walls not to remove chatter marks
If it removes the mark it also would make the chamber bigger
With any method
Stoning included.
A " t " handled polishing stick with a paper roll on it.
Well I can't use the common name the instructor called them as it was a course word.
This is to smooth the chamber walls not to remove chatter marks
If it removes the mark it also would make the chamber bigger
With any method
Stoning included.
Guncrank
By TSJT I assume you mean Trinidad.Cool,good school.
I never went there.
In my trade of designing and building plastic injection molds,I learned a little different style than most gunsmiths .
My employer sent me to Chicago to understudy a master mold and die finisher.The US Mint had him polishing coining dies when I walked in his shop.He immediately put me to work polishing the cavities for a mold to make plastic spray can covers.
There are satellites in the sky that have miirors of tungsten carbide I hand polished to a total variation from flat of .0001.At least that was the spec'd tolerance,and the people building the satellite sent back compliments.
What is good for all of us to realize,there is an incredible range of experience and skills among the members of this forum.
It might be fair to say I could give your instructor at TSJC lessons on polishing.
I am very happy to pass on what I know,but I just am not interested in struggling.You go right ahead and do it the way you do it.
Ever used a DME profiler?Got one on my toolbox.Variable strokes 0 to about 1/4 in,0 to 14,000 strokes a minute.I float laps and stones with it using a pick.You know the Fordhem grinder,yes?I have a 1/2 hp 10,000 rpm version,thakes 1/4 in tools in the collet.I go down to a little 90 degree 175,000 rpm dental grinder.I have bulk 1 in thick rock hard felt I hole saw buffs out of.Cast iron laps?Do you know whay a puddle stone is?A stone like a Gesswein is sintered and vitrified.Its not good when the grit breaks down in a clump.That clump digs up your work.A puddlestone is like a japanese water stone.It won't do that.I do most of the rest with number 9 and number 12 diamond compound.
I can polish over edges,holes,lettering,and leave the edges flat,crisp,and sharp
For most of the mold work I did,the plastic part had to fall within common tolerances for a chamber.My work had to be 1/10th that tolerance.If the tolerance was .004,I got .0004.
My mentor is probably dead.The skills of old masters are like gold!I'm trying to give it away.
By TSJT I assume you mean Trinidad.Cool,good school.
I never went there.
In my trade of designing and building plastic injection molds,I learned a little different style than most gunsmiths .
My employer sent me to Chicago to understudy a master mold and die finisher.The US Mint had him polishing coining dies when I walked in his shop.He immediately put me to work polishing the cavities for a mold to make plastic spray can covers.
There are satellites in the sky that have miirors of tungsten carbide I hand polished to a total variation from flat of .0001.At least that was the spec'd tolerance,and the people building the satellite sent back compliments.
What is good for all of us to realize,there is an incredible range of experience and skills among the members of this forum.
It might be fair to say I could give your instructor at TSJC lessons on polishing.
I am very happy to pass on what I know,but I just am not interested in struggling.You go right ahead and do it the way you do it.
Ever used a DME profiler?Got one on my toolbox.Variable strokes 0 to about 1/4 in,0 to 14,000 strokes a minute.I float laps and stones with it using a pick.You know the Fordhem grinder,yes?I have a 1/2 hp 10,000 rpm version,thakes 1/4 in tools in the collet.I go down to a little 90 degree 175,000 rpm dental grinder.I have bulk 1 in thick rock hard felt I hole saw buffs out of.Cast iron laps?Do you know whay a puddle stone is?A stone like a Gesswein is sintered and vitrified.Its not good when the grit breaks down in a clump.That clump digs up your work.A puddlestone is like a japanese water stone.It won't do that.I do most of the rest with number 9 and number 12 diamond compound.
I can polish over edges,holes,lettering,and leave the edges flat,crisp,and sharp
For most of the mold work I did,the plastic part had to fall within common tolerances for a chamber.My work had to be 1/10th that tolerance.If the tolerance was .004,I got .0004.
My mentor is probably dead.The skills of old masters are like gold!I'm trying to give it away.
H
Ahha sorry to offend a master polisher
And no that is not ment as a smart aleck remark
No I don't have a D profiler
Know all about Gesswin stones and DME
Have a assortment of several hardness and grades.
I have knowledge of your type of work.
Trained as a moldmaker on injection molds.
I was pointing out or trying to point out that no method of polishing will remove a scratch in chamber without making said chamber out of spec.
You said same thing , just a more technical way.
I polished the dies I made but the optical Len dies went to a guy like you to finish
Which we had a teacher like you at school but alas not the case.
A split polish stick like I said is just to slick up a chamber not remove scratches.
Keep posting as I said in another thread, stop learning and you stop being the best you can be.
Ahha sorry to offend a master polisher
And no that is not ment as a smart aleck remark
No I don't have a D profiler
Know all about Gesswin stones and DME
Have a assortment of several hardness and grades.
I have knowledge of your type of work.
Trained as a moldmaker on injection molds.
I was pointing out or trying to point out that no method of polishing will remove a scratch in chamber without making said chamber out of spec.
You said same thing , just a more technical way.
I polished the dies I made but the optical Len dies went to a guy like you to finish
Which we had a teacher like you at school but alas not the case.
A split polish stick like I said is just to slick up a chamber not remove scratches.
Keep posting as I said in another thread, stop learning and you stop being the best you can be.
HiBC,
Do you mind sharing a source of the hard felt stock?
Guncrank,
I've done a fair amount of fire lapping, and I don't find the bore reamer marks are usually more than about a ten thousandth or two deep (a slug shows it has opened up maybe a quarter to a half a thousandth at most by the time all the abrasive marks are scratched longitudinal. I assume most chamber marks, unless there's a real gouge, are similar in RMS surface roughness. Given the +0.002" typical SAAMI chamber diameter specs, unless your chamber is at that maximum, taking off a tenth to a quarter thousandth shouldn't really take the chamber out of spec. But you do need to know what you are starting with and I've seen a few pretty fat AR chambers (5.56 NATO spec) that I would not want to enlarge any.
I agree that using the reamer correctly in the first place is the main key. I got one of Greg Tannel's through-bore pressure cutting fluid systems years ago, and if everything is set up right on the lathe and you use a reamer whose pilot has lube passages ground in, you wind up with one very smooth chamber finish from the git-go.
Do you mind sharing a source of the hard felt stock?
Guncrank,
I've done a fair amount of fire lapping, and I don't find the bore reamer marks are usually more than about a ten thousandth or two deep (a slug shows it has opened up maybe a quarter to a half a thousandth at most by the time all the abrasive marks are scratched longitudinal. I assume most chamber marks, unless there's a real gouge, are similar in RMS surface roughness. Given the +0.002" typical SAAMI chamber diameter specs, unless your chamber is at that maximum, taking off a tenth to a quarter thousandth shouldn't really take the chamber out of spec. But you do need to know what you are starting with and I've seen a few pretty fat AR chambers (5.56 NATO spec) that I would not want to enlarge any.
I agree that using the reamer correctly in the first place is the main key. I got one of Greg Tannel's through-bore pressure cutting fluid systems years ago, and if everything is set up right on the lathe and you use a reamer whose pilot has lube passages ground in, you wind up with one very smooth chamber finish from the git-go.
Un
If you have a scratch in the chamber it will be from a chip stuck in a flute or chatter from a fouled or dull reamer.
That is probley be more than .0002 deep
It that is the case no polish will remove that without making a chamber out of round.
Now a scratch could be less than that and polished out but not from my experence.
A deep scratch polishing should at least reduce the edge that the case would stick too.
Polishing a chamber to remove rust is the main job that I run in my shop.
The OP has feeding scratches not chamber scratches.
If you have a scratch in the chamber it will be from a chip stuck in a flute or chatter from a fouled or dull reamer.
That is probley be more than .0002 deep
It that is the case no polish will remove that without making a chamber out of round.
Now a scratch could be less than that and polished out but not from my experence.
A deep scratch polishing should at least reduce the edge that the case would stick too.
Polishing a chamber to remove rust is the main job that I run in my shop.
The OP has feeding scratches not chamber scratches.
Last edited:
Uncle Nick
My company at the time,mid-late 90's bought a sq yard of 1 in rock hard felt and it was $900.For myself,from my company,I bought 1 sq ft for $100.
Its not cheap.I looked on the web some,wan't sure.What I did do is look to see if the Chicago mold polishing outfit that trained me is still in business.The son is running it and I met him.I will give him a call soon,see if he will recommend a supplier.
My company at the time,mid-late 90's bought a sq yard of 1 in rock hard felt and it was $900.For myself,from my company,I bought 1 sq ft for $100.
Its not cheap.I looked on the web some,wan't sure.What I did do is look to see if the Chicago mold polishing outfit that trained me is still in business.The son is running it and I met him.I will give him a call soon,see if he will recommend a supplier.