Gouges/Lapping new barrel?

[Edd]

In post #57 i read in the last sentence that you fire lap all your personal barrels after they are chambered…
Confused?
—-
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?

His reply, " ....... "

 

[JFrank]

I find the thought of lapping a premium barrel that’s already gone through the process somewhat distasteful.

 

[ELR LVR]

His reply, " ....... "

Got it, very interesting.
I just read some on a thread here of fire lapping.
The barrel maker likely has a good process and done his research like Tubb has.
Interesting even a barrel maker uses that method on his own barrels

 

[ELR LVR]

I find the thought of lapping a premium barrel that’s already gone through the process somewhat distasteful.

Well, no more than taking a custom bullet and reworking it over in some way such as pointing, meplat trimming etc.
As good as our custom components are, they’re not all always perfect
Its not as though i lap a barrel for no good reason just for the fun of it lol.
It is time consuming and Id rather not, but my results have shown the time to be worthwhile

 

[JFrank]

Well here’s the difference, if you F up a bullet or two it’s just a couple dollars and the rest of the lot of bullets whether 500 or 1000 are still fine but how do you un lap a premium barrel ?
I don’t think it’s possible to reverse the deed.

Each to their own of course …

 

[ELR LVR]

Well here’s the difference, if you F up a bullet or two it’s just a couple dollars and the rest of the lot of bullets whether 500 or 1000 are still fine but how do you un lap a premium barrel ?
I don’t think it’s possible to reverse the deed.

Each to their own of course …

True, but when I machine, thread and chamber a barrel, i also can’t reverse an F-up there neither.
There’s many more risks involved in that process than there is in hand lapping.
—-
Me and my buddy invented a type of infinitely progressive transmission once similar to a CVT. I asked him , “how are we going to make it so it doesnt break if its always in its peak torque curve”
His answer was simple
“We’ll just have to make ‘em good”
—-
The answer is simple
Just don’t F-up

 

[L.Sherm]

I cannot imagine removing tool marks in 30 passes with the equivalent of 600 grit.

You gotta realize I'm talking very faint ones like only being able to see with a Hawkeye borescope after bore reaming and not using very aggressive lapping acompound at all.
When I pre lapped I was after 2 things getting rid of any circular marks made by the bore reamer and the finish in the barrel.

 

[ELR LVR]

This is very similar to what I do…
Quote from JE CUSTOM
—-
Use xxx grit non embedding compound- dont use valve grinding compound (Too aggressive).

Using an old bore brush with some of the bristles ground off then end (About half way down the
brush )place the brush in the bore from the reciever end about 1'' from the muzzle.
—-(I do approx 1.5 to 2 inches for more surface area)

Next ; Melt some tire weights or plumbers led and carefully pore the led down the barrel until it
fills to the top.
—- (I use hard cast bullet lead)
After cooling you can push the casting out the crown and trim the sprue off. I would recomend that you practice this step until you can cast a good pill.

When you have that mastered, apply a small amount of lapping compound to the casting and insert it back in the muzzle with the cleaning rod attached threw the action/breach.
—-( i cut ring grooves in the lead lap to hold compound and provide relief for built up material)
Note do not turn the broach around backward and enter from muzzle. place it in the same location and orientation as it was cast. (Mark/clock your 12’o clock)
Carefully start the broach by hand in the rifling. once started place the barrel horizontal and begin to lap never allowing the casting to exit the barrel.
—-(i lap the first 50% of bore first, next 25% added to the 50% so the i am doing 75% of bore next. Add the last 25% of bore so you lap the full length and of bore last, this will help ensure a minuscule taper, and prevent any belling of the muzzle end)

A word of caution: don,t over do it , lapping causes barrel wear and shortens life . so this is a case
of "Less is More" . only lap enough to smooth some of the tool marks out. the bullet will do the rest
with time.

If lapping is done incorrectly it can ruin a good barrel, so practice on an old or take off barrel first and then if you are still intent on proceeding , be careful.

J E CUSTOM

 

[ELR LVR]

You gotta realize I'm talking very faint ones like only being able to see with a Hawkeye borescope after bore reaming and not using very aggressive lapping acompound at all.
When I pre lapped I was after 2 things getting rid of any circular marks made by the bore reamer and the finish in the barrel.

Agreed, we aren’t seeking to actually remove enough material to change dimensions,
(I once tried sandpaper and Valve lapping compound on a tight chamber of a Krieger to enlarge it slightly…using a brass cartridge as the lap for the back end.
After an hour in the lathe I didnt even move it up .001”. Which shows its not as easy to mess a barrel up as one thinks if you use the right tools and compounds to be able to go slow and carefully.
The wrong tools and compounds of course can ruin anything quickly.
The key is only doing what is necessary and tools that only allow slow progress.
IE- we’re not removing the sharp teeth off the file until it is smooth, but more dulling the sharp edges and smoothing tight spots for smoother bullet transition.
If there is a tight spot, you wont really remove any from the rest of the bore anyway because the lead lap will swage down to the tightest diameter and really only work that tight spot out.
As well as smooth any sudden changes in twist of the rifling.
Every machine has play and slop
No machine including CNC can hold exact tolerances simply due to bearing play and temp difference.
You got it right man

 

[Sniperhandle]

I have never lapped a barrel, But The only thing I disagree with on JE Customs method is this, Barrel makers usually try to make the muzzle end of the bore tighter, So molding your lap at the muzzle would in theory make it too small for the other end of the barrel, Just thinking out load.

 

[ELR LVR]

I have never lapped a barrel, But The only thing I disagree with on JE Customs method is this, Barrel makers usually try to make the muzzle end of the bore tighter, So molding your lap at the muzzle would in theory make it too small for the other end of the barrel, Just thinking out load.

When you get a barrel blank…
Which end is the muzzle end?
Haha just razzin’ ya
—-
You raise a good point,
After a rifle is built the smith often tries to make the muzzle end the tight end.
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I read lots of other guys methods who lap their barrels.
One I found very creative.
He slits the end of the lap.
Drills a hole in the end of the lap
Then uses a taper screw to adjust tension on the lap and take up slack as the very much softer lead wears down.
A guy could easily slit and shim to accomplish the same.
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I repour a new lap as needed if needed instead. I dont want lead shavings or dust anywhere if i can prevent it