Barrel lapping

[jake]

Can anyone give me some info on barrel lapping,is it hard to do? Does it help with the accuracy. I have a 209-50 it shoots pretty good but I'm always trying to get it perfect. Is it worth doing?

Thanks for you're help :-)

[KING]

I would  do the lapping last...try some more combinations outta it first..to get the groups that u want........when i did my tc lotsa years ago i first slugged the barrell...i then took that slug and coated it with lapping compound and passed it through the barrel about 30 times ..i was using a find grit,,i think it was 600...but...i did not know what i was doing at the time,and if ya screw up,the barrell is pretty much destroyed,and they are expensive...when u say yours shoots pretty well..i would leave it at that...there is probable a lot of others that can tell ya how to PROPERLY LAP THE BARRELL...I was just trying to get the sharp edges off so i would not cut the  patches.....Ya have to temember that just about any gun is a critter unto itself....it takes a lot of voodoo and witchcraft sometimes to get what ya want in group size

[AJ]

What some so called experts are calling lapping is actually cleaning.  They are using JB Bore Cleaner, Flitz, or Simichrome on a patch and scrubbing the bore a couple hundred times.  This is mearly cleaning the junk from the barrel.  

Lapping is what King mentioned, using a lead lap that has actual lapping compound imbedded in its surface.  It has to match the bore perfectly.  Insert a couple patches to create a dam.  A cleaning rod is inserted into the bore with an old worn out brush.  Molten lead is poured into the bore to form a slug.  Push the lug about halfway out of the bore and coat with abrasive compound and oil slurry.  Run the slug back and forth in the bore.  Remove the slug and thoroughly clean the bore with solvent to remove any abrasive particles.  Repeat the entire above process with finer grit.  You do need a new slug for each grit.  

The problem with lapping is at the spot where the lap is stopped and the direction is changes, it has a tendancy to remove more material.  Typically, barrel makers do this prior to fitting the barrel as they will cut off the last inch or more of the barrel where it is hogged out.  The chamber will take care of the other end.  On a blackpowder gun there is not chamber, but the muzzle end can get messed up.  

If you decide to try either method (lapping or cleaning), always use a bore guide.  You can have the most polished bore and smooth lands but if the crown is damaged, your accuracy is ruined.  I use a rod guide every time a ramrod goes into the bore.  Yes, I carry one in the woods for reloads.

[Rock Home Isle]

THREAD RESSURECTION

I bought a Pedersoli Alamo Rifle in .50 calibre...years ago. I could not get the gun to hit the broad side of a barn at 5 yards. Needless to say I was very disapointed in my purchase. I mentioned my problems to my boss (at the time) and he turned out to be a very knowledgable muzzleloader. He had me bring the gun in and he explained what to look for when inspecting a firearm...he was a great boss. The he looked at the patches and suggested that I lap the barrel...I had no idea what the heck he was talking about...

Since that time I have lapped 3 muzzle loaders. In each instance the barrel would produce torn, damaged or marred patches and accuracy from the firearm inquestion left a lot to be desired. An inspection of the muzzle showed that the crown was in good to excellent condition, meaning that the barrel didn't need to be re-crowned; the barrel was solid, the stock well maintained, all the mechical parts were in working order and in good condition. The accuracy problems lay within the barrel.

I would clean the barrel very throughly. Then I used valve grinding compound rubbed into a clean patch. I limited the lapping to 20 or 30 strokes, and faterwards the barrel is very throughly cleaned.

In each instance, the next trip to the range produced nice tight groups...accuracy was much improved.

[Rock Home Isle]

I should add that since I lapped that barrel of that Alamo .50 cal. it became my prime firearm for many many years. It took many elk, several of them were big bulls and I have lost count of how many deer.

Wow, what a tack-driver.

[coyotejoe]

Agreed, what most people call "lapping" with grit on a patched ball, is enough to take the burrs and sharp edges off the lands and that may be all that is needed. However, I have often found loose and tight spots along the length of the bore and those need to be evened out by actual lapping with a cast slug, some fairly aggressive grinding compound and a lot of work. If done properly, lapping can even produce a choked bore which is quite beneficial to accuracy. I have made myself a special lapping rod with a large two handed T handle using a bicycle front wheel hub for ball bearings of rod to handle. It takes a lot of time and effort to enlarge a rifle bore by .001".

[Swampman]

I would consider it on a baddly pitted barrel but I can't see wearing a barrel on purpose.

[Rock Home Isle]

Agreed, what most people call "lapping" with grit on a patched ball, is enough to take the burrs and sharp edges off the lands and that may be all that is needed. However, I have often found loose and tight spots along the length of the bore and those need to be evened out by actual lapping with a cast slug, some fairly aggressive grinding compound and a lot of work. If done properly, lapping can even produce a choked bore which is quite beneficial to accuracy. I have made myself a special lapping rod with a large two handed T handle using a bicycle front wheel hub for ball bearings of rod to handle. It takes a lot of time and effort to enlarge a rifle bore by .001".

Somewhere I have a book that explains the exact process that you are describing...and as soon as I find it I'll post the source. This method that you have presented is the TRUE Lapping of a barrel.

What I described in my post is a quick and dirty method designed to tune a specific accuracy problem.

[Longknife 76]

If it loads smoothly, no tight or loose spots and your shooting patches are not cutting, you do not need to lap!!!!!!!!!!

[coyotejoe]

Well yeah, if it ain't broke don't fix it but most barrels will benifit from lapping.

[Rock Home Isle]

Well yeah, if it ain't broke don't fix it but most barrels will benifit from lapping.

I quite agree...I will lap a barrel as a last resort.

In the 2 instances where I have lapped a barrel the results have been positive.

[Buckskins & Black Powder]

Wheeler sells this lapping compound that you rub onto your bullets and fire lap it,
http://www.battenfeldtechnologies.com/wheeler-engineering/catalog.asp?family=lapping-compound

[Rock Home Isle]

That lapping compound looks like a cool product. 

[Swampman]

Few barrels benifit from lapping.

[coyotejoe]

And that opinion is based on what?
 I have lapped half a dozen round ball barrels and ALL were very much more accurate, easier to load and easier to clean after lapping. I have a good friend who is a very serious shooter. He buys Green Mountain barrels and laps them first thing before he ever fires the first shot because he says he knows they will need it to achieve the kind of accuracy he demands.

[Swampman]

Just a feel good old wives tale like breaking a barrel in.  It doesn't do a thing except wear the barrel out.

[Semisane]

   You may as well give it up right now coyotejoe.  Our buddy Swampman has strong opinions that won't be changed.   

Personally, I've had excellent success firelapping three barrels with Beartooth Bullets lapping compound (https://beartoothbullets.com/bulletselect/index.htm) using the recommended method (http://www.beartoothbullets.com/tech_notes/archive_tech_notes.htm/48).  On two others I saw no change, either good or bad.  I fire lapped a .41 Mag Ruger Blackhawk and it went from four-inch twenty-five yard groups to one-inch groups.

[Swampman]

Most that promote lapping sell lapping products.  Many who promote barrel break in sell barrels.

Most barrels improve with shooting.  Lapping is like running a couple of thousand rounds down the barrel.  That's more than 1/2 the life of many barrels.

I've seen it all and tried most of it.

Snake oil is snake oil.

[Semisane]

Told ya.   

[Rock Home Isle]

Wheeler sells this lapping compound that you rub onto your bullets and fire lap it,
http://www.battenfeldtechnologies.com/wheeler-engineering/catalog.asp?family=lapping-compound

Have you tried this product?? I'd like to hear more about it..

[quickdtoo]

You can read the reviews at Midway.

Tim

http://www.midwayusa.com/viewproduct/?productnumber=646612

[Rock Home Isle]

Very Nice...Thank you for the link. 

[Buckskins & Black Powder]

Wheeler sells this lapping compound that you rub onto your bullets and fire lap it,
http://www.battenfeldtechnologies.com/wheeler-engineering/catalog.asp?family=lapping-compound

Have you tried this product?? I'd like to hear more about it..

No i havent tried it yet. I plan on giving it a try and watch the bore and see how it looks after about 40-50 rounds.

[Rock Home Isle]

Hey bigblock455 thanks for the heads up on this product. I do have a rifle that is giving me fits as far as accuracy...I'll be giving this a try.

[coyotejoe]

Most that promote lapping sell lapping products.  Many who promote barrel break in sell barrels.

Most barrels improve with shooting.  Lapping is like running a couple of thousand rounds down the barrel.  That's more than 1/2 the life of many barrels.

I've seen it all and tried most of it.

Snake oil is snake oil.

 Swampman, I'm not selling anything nor attempting to promote lapping, I'm just speaking of my own personal experience of having done the work and seen the results, where as you are postulating from a base of ignorance. Lapping does not "wear out a barrel". On the contrary, a properly lapped barrel is not only more accurate but it will retain its' accuracy longer.
 I am speaking of lapping with a cast lead slug, not fire lapping nor running a gritty patch or Brillo pad up and down the bore. Not that those techniques are necessarily bad, just not what I'm talking about. Real lapping smooths and uniforms not just the top of the lands but the bottom of the grooves and the sides of the lands. All high quality "match grade" barrels are hand lapped and I'm sure I've never seen a barrel maker proclaim, "buy our barrels, they're half worn out!"

[Swampman]

I've seen, heard, and tried all of it and helped others with it.  It's snake oil.

[necchi]

Well said coyotejoe, I aggree with you 100%.
 The simple truth however, is most folks don't have the time nor patience to do a true and full, consiencous lapping. It's an hours long job that's delegated not to an apprentice, but a journymen in a pro shop, because it is a delicate task.
 Many can't even take the time to clean the heavy packing grease in most new barrels properly, and wonder later why their new barrel or gun isn't shooting well.
 Everybody wants a quick fix, squrit this stuff in and stroke 10 times, rub this stuff on and shoot 5 times. It is a panacea affect, "Oh miracal of miracals" I can shoot now,,,if it where a double blind test, the results would be different.
 For most the idea of a pound of powder and a 100 ball spent in load development finding something as simple as a good patch/lubed combination is lost, they get half-way into it, decide it takes too much time, besides that's "gud enough", then later they just know it's the wrong lube,,,,,
 With a new barrel, after a white patch comes out white, I'll take about a 100 strokes with a polishing compound and snug patch,(not a rubbing compound), several patches AND a bore guide, then start shooting. The barrel usually begins to dial in after 150-200 shot's. I guess I'm not a short-cut guy, by then I know that gun.

[Swampman]

Of the hundreds of guns I've owned I did have 2 that took a little work to get them to shoot.  Everything I've ever owned with the exception of those 2, shot very remarkable groups without any work at all.  Maybe I'm just living right, or maybe I'm just lucky and lazy.

No snake oil thanks.

[coyotejoe]

Necchi, I hear what you're saying but in reality I lap bores because it is much quicker, easier and less expensive than loading and firing those 100-200 shots to break in a barrel, not to even mention the time and expense of several trips to the range.
Swampman, I for one still remember your rants about how Thompson/Center barrels are good only for tomato stakes. Now you seem to be buying T/C's by the dozen and I guess they all shoot "remarkable groups" because they are now your guns. Yes, you are lucky indeed.

[Swampman]

Accuracy is dependent on the gun holder.  I just don't have accuracy problems.....ever.

All my T/C either have or will have GM barrels.  I can't pass up nearly free stocks, triggers, & locks.