Gouges/Lapping new barrel?

[Hal]

TA

What lapping compound do they send you to use?

Hal

 

[TA17rem]

LOL. I don't know, it comes in small container unmarked. Could be JB bore paste.

 

[ELR LVR]

TA

What lapping compound do they send you to use?

Hal

To lap a barrel properly you should pour a lead slug.
Then use diamond compound of your choice which can easily be found on EBay.
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If I Remember correctly
Military specs have called for
32 micron
Kreiger uses 16 micron.
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Dont quote me since it was a long time ago I read those numbers.
You may start with 400 grit and progressively work up to however fine of a finish you want.
Remember we avoid a perfectly polished bore for copper jacketed bullets.

 

[L.Sherm]

If you gotta lap a barrel after its made then there process needs to change.
On a button barrel if everything was done correctly before the button was pulled then all that should have to be done is clean it before it goes to heat treat.
I dont want any barrel I have to lap after its made.
Now that being said a smith ive used for years called me he was having a problem with a brand of barrel not shooting untill it got 50-100 rounds on it so I looked at the inside of one he had i could tell right away the finish lapping wasn't right I put a finish lap on it and made big difference.
Lead lapping a barrel is to take high spots out of a barrel its the only way to get it uniform from end to end

 

[tobnpr]

I dont want any barrel I have to lap after its made.

Preach...

 

[L.Sherm]

Preach...

Do you?

 

[tobnpr]

Do you?

Eff NO. I'm in agreement Pretty sure I know what Frank Green would say about someone lapping a brand new Bartlein...

 

[deertroy1]

looks like a cleaning rod or indicating rod did this from what I have seen.. If its a Brux I could try and lap it out but no guarantee it would come out. I have seen a ton of guns that shoot lights out with cleaning rod damage.

It's not a Brux but your offer, if it was, speaks very highly of your company.
The marks were there before I cleaned it and as I stated, I'm very careful, use a bore guide, coated rods, etc.

 

[deertroy1]

Is the material pushed up towards the chamber?

Shawn Williams

It's hard to tell.

 

[ELR LVR]

Re:
Lapping a barrel after its made…
We have to consider WE PAY for the production costs.
Barrel lapping in my opinion is done to
“Good Enough “ standards and that people are willing to pay for.
I can almost guarantee, if everyone slugged their barrel and prepped to lap, they would find
SOME irregularities in their bore.
You wanna pay an extra$100 for half a ten thou?
Most wouldn’t
——
And I agree. I dont want to pay $700 for a barrel just because it has a better hand lapped finish…
When I can buy good enough
For $500
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Lapping CAN be taken to a next level though.
But what we personally pay for is merely to knock edges off and help relieve any barrel break in.
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Something can always be done better.
Cut rifled va hammer forged
ECM MACHINED VS cut rifled
Etc.
Uniformity to within .0001”
Vs uniformity to within .000005”
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What is good enough and what are you willing to pay for?
I offer my lapping services even
The only takers I get are airsoft guys.
Which shows, most people settle for “good enough “
Simply because thats all they’re willing to pay.
And I agree.
i aint paying no $900 for a carbon wrapped barrel for example lol
There used to be teflon coated barrels, we dont see that anymore.
Why?
People arent willing to pay for it.
Our barrels our dang good for $500.
Nobody is gonna offer a more perfect barrel for $1000 though because the $500 barrel is good enough for what everyone does.
—-
People even live with their 200 round break in and accepted barrel speed up.
Does that show something?
—-
With piloted chamber reamers, we have pilots offered in .0001” increments. If every barrel was perfect we would only have one size bushing for every caliber.
Does that not also show something?

 

[ELR LVR]

Eff NO. I'm in agreement Pretty sure I know what Frank Green would say about someone lapping a brand new Bartlein...

If I do so, Frank would probably say
“Wow, we ought to to have him final lap our barrels”
But it comes down again to ,
What people are willing to pay
He wouldn’t want to pay what it would cost, and neither would the customer.
It’s similar to when I do trigger work.
I do triggers for half my normal labor rate, simply because nobody would pay what it would actually cost.
Nobody is gonna pay $250 for a 1.25 lb factory Rem trigger, right?

 

[L.Sherm]

uniformity to within .000005”

Can you measure that or does that matter in a barrel?
I know in a button barrel if the drilling and bore reaming is done properly its about 30 pre laps to get all the tooling marks out to the finish you want before the button is pulled takes about 10 minutes tops.

 

[ELR LVR]

Can you measure that or does that matter in a barrel?
I know in a button barrel if the drilling and bore reaming is done properly its about 30 pre laps to get all the tooling marks out to the finish you want before the button is pulled takes about 10 minutes tops.

No I don’t think it would matter except in theory but.
If we think in terms of the type of pressures going on and fluid dynamics….
We dont want ANY portion of the bore to “enlarge” since this would allow gas to escape past or around the bullet right?
(Flame cutting may happen then)
So we see barrel mfgr’s advertising uniformity to within.0001”
—-
Ideally we would want perfect uniformity down the bore right?
So i just used that number to represent uniformity to as close to perfection as would be realistic.
In the millionths of an inch
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The second option would be to possibly constantly be squeezing to provide an ongoing perfect seal as the bullet travels down the bore.
No possible escape around the bullet as it travels.
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What i do know is, every barrel I have taken to lap myself to improve the finish, I have improved the barrel. And i have 90% of the time felt “something feel different “ somewhere along the bore. Even if it was just one small spot.
If something feels different, it is different, and its not the lap that suddenly changed dimension.
You know this when go past that spot then back up and feel it in the same exact spot, that its in the barrel.
Rarely does a barrel feel perfect and i say “this barrel needs nothing done “
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It helps to already be a machinist knowing procedures to think a job all the way through first, take as much time as is needed and not rush a job. Therefore…
…I have never gotten lap happy and over-lapped a barrel to the point of ruining one which is likely why every one i have done has improved it in one aspect or another.

Even if it were simply improving it to be able to clean up faster and not copper up.
Like i say my own process is more of a final finish that I have found works and the top barrel makers do a good job already to begin with. I simply take it a final step further.
Even if it’s simply to check uniformity in the dia. Or land/groove width.
I did have a tight bore once which is when i started lapping even my top brand barrels.
Another reason i will lap is for an old barrel that may have had pitting. This smooths up the leading and trailing edges of the pits. Shown is just one example of a Rem 788/.222 i lapped for just that reason and how it shot after i got done.
If a gun don’t shoot like an old factory Rem. / I may choose to lap

 

[ELR LVR]

Can you measure that or does that matter in a barrel?
I know in a button barrel if the drilling and bore reaming is done properly its about 30 pre laps to get all the tooling marks out to the finish you want before the button is pulled takes about 10 minutes tops.

Let me just say,
The finish “I Want”
From my own experience and test results.
Cannot be achieved in just 30 passes.
Thats pretty aggressive removal
I cannot imagine removing tool marks in 30 passes with the equivalent of 600 grit.
You have to progress up to the finish you want just like using progressive grits of sandpaper to have as uniform finish as possible without leaving the gouges of the previous finished grit behind
IE: you wouldn’t start at 240 and jump right to 600.

 

[gunsandgunsmithing]

I'm not a bbl maker but I did sleep in a Holiday Inn last night, so...I strongly suggest anyone reading this to consult with your bbl maker before lapping your premium bbl. I also suggest you hold the phone a few feet from your ear when he replies.

 

[ELR LVR]

I'm not a bbl maker but I did sleep in a Holiday Inn last night, so...I strongly suggest anyone reading this to consult with your bbl maker before lapping your premium bbl. I also suggest you hold the phone a few feet from your ear when he replies.

Yeah dont expect to lap your own barrel and be able to send it back
Thats on you if you choose to.
Just dont go learning on your hummer 6PPC….mkay

 

[Edd]

A few years ago I asked the owner of a barrel mfg, a name everyone would recognize, about fire lapping a newly chambered barrel. His reply, "we don't approve of it because we have no control over what someone might do during the process. But I fire lap all of my personal barrels after they are chambered."

 

[ELR LVR]

A few years ago I asked the owner of a barrel mfg, a name everyone would recognize, about fire lapping a newly chambered barrel. His reply, "we don't approve of it because we have no control over what someone might do during the process. But I fire lap all of my personal barrels after they are chambered."

I’ve never fire lapped
The idea scares me with regard to
Control
I rather have control over speed, feel, grit # etc.
Whats your results though?
All good?
50/50?

 

[Edd]

What's your results though?
All good?
50/50?

I have never fire lapped a barrel.

 

[ELR LVR]

I have never fire lapped a barrel.

In post #57 i read in the last sentence that you fire lap all your personal barrels after they are chambered…
Confused?
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Or did i interpret that wrong and you were saying that
The well known Barrel Maker himself,,,fire laps his own personal barrels after chambering?