Barrel Lapping....opinions?


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Rembrandt
April 23, 2007, 09:33 PM
Bought a new rifle over the weekend, seller recomended it be lapped. Did a search and found conflicting views on this. One person that poo-poo'd it was Gale McMillian. I'm inclined to go with his opinion, but there are so many others that are as convincing it does help. Is there any difinitive proof to support either view?

(Here's McMillian's take... http://www.snipercountry.com/Articles/Barrel_BreakIn.asp )

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USSR
April 23, 2007, 09:41 PM
Rembrandt,

Define "lapping"? Or are you talking about barrel break-in? Two totally different things.

Don

DMK
April 23, 2007, 10:32 PM
Fire lapping (http://www.bellmtcs.com/FAQ/Fire_Lapping.htm)?

Rembrandt
April 23, 2007, 10:38 PM
As I understand it, lapping is the process of casting a lead slug of the bore, then using abrasive paste & slug to take out rough machine marks. Another process is to use fine abrasive impregnated bullets fired through the barrel (fire lapping) to achieve the same thing.

I believe the break-in process is the firing of a few rounds and cleaning, then repeating the process over and over for the first few hundred rounds.

I think some incorporate both the firelapping and break-in procedures....is that correct?

rangerruck
April 24, 2007, 04:20 AM
if you can afford it, lapping is a very good idea. After all do you wanna break in a bbl, that has the surface of a sponge, and you will soon fill up that sponge , with copper lead, powder, peas, potatoes, corn , etc., or do you want your first shots going down a mirror smooth bore?

Jim Watson
April 24, 2007, 09:08 AM
Rembrandt, I think you have the basics down pretty well.

Hand lapping is a skill process and I would not undertake it promiscuously on the typical factory rifle. (What did you buy, anyhow?)

I fell for the Tubb Final Finsh version of fire lapping and shot gritty bullets through two barrels. I had broken in a factory barrel very laborously and it did not do much for it. It coppered and did not shoot as accurately as the Internet Experts said it should. The Final Finish procedure smoothed the factory barrel and made it easier to clean and also advanced the throat measurably. It did not make it more accurate.

I replaced the factory barrel with a name brand "hand lapped" job. I did not fire lap it but went through the manufacturer's 40 shot break-in which gradually reduced its tendency to copper... which was not nearly as bad as the factory barrel to start with.

The other was a good quality name brand hand lapped barrel. I had put it through the maker's 13 shot break in when new but had it rethroated for a different bullet just before I got into the Tubb system. So I just shot the finer grits in accordance with Tubb's recommendation. It did not affect that barrel any way I can tell, cleaning, accuracy, or throat length.

I have some Final Finish bullets that I may use to try to smooth up an old and somewhat eroded barrel, but I doubt I would put them through a new barrel again.

As far as the break in rituals, I figure I would follow the maker's recommendation. If I had a McMillan barrel, I would not break it in; otherwise, do as the maker says. None I have seen ran to a hundred rounds, and the late stages of the 40 round session above was good for load development and zero so it was not a waste of barrel life; that shooting would have had to been done anyhow.

NavyLCDR
April 24, 2007, 09:45 AM
I have a circa 1913 Frech Berthier rifle in 8mm Lebel. I clean the barrel with standard copper solvent from Walmart and get blue on the patches everytime after shooting. When the barrel is clean, I get 5-7 shots that are perfect - one hole right at POA at 30 yards - it's amazing! Then after 5-7 shots the bullets begin to stray even from a cold barrel.

Do you think the Tubb's fire lapping method would help with this? I've been told this can be cause by a bur in the barrel that strips copper from the bullet jacket and the stripped off copper builds up to a point where it affects accuracy.

USSR
April 24, 2007, 11:42 AM
Rembrandt,

Lapping: As previously mentioned, should only be done by the barrelmaker, and is typically only done by makers of high quality custom barrels. It's purpose is to remove machining marks created by boring the barrel that are non-parallel to the bore.

Barrel break-in: Designed to remove non-parallel machining marks in the throat by shooting naked bullets and then immediately removing the copper that is deposited in the bore by the throat. The throat is not affected by a custom barrelmaker's lapping, so even high quality custom barrels need to have the throat smoothed out by shooting.

Fire lapping: A Hail-Mary approach used on military or factory barrels that copper foul quickly with resultant inaccuracy. Expect the throat to lengthen when doing this. Should only be done as a last resort.

Don

eliphalet
April 24, 2007, 12:26 PM
One person that poo-poo'd it was Gale McMillian
Tell ya what, you find someone with more knowledge and experience that Mr. Gale McMillan and maybe I would do what I consider the foolishness of "barrel break in" I have a 223 all I have done is shoot it plenty bring it home after 10 or heck maybe 200 rounds and run a patch or two through it at home. Last time I papered it she shot a 9/16 five shot group with mixed military brass with surplus 55gr. FMJ's loaded with a Lee powder dispenser. I also have 50 year old Winchester that some years didn't even get cleaned after being shot till hunting season was over and it shot me a 13/16 group with el cheapo cor-locks hand loaded the same way.

IMHO fire lapping and barrel breaking is a joke. and if you do that to your poor gun the jokes on you. Sorry guys but I do believe "barrel break in" it is just more hype pushed at us to sell products we don't need. But it's your gun so do what you wish. It is no ones business but yours.

glimmerman
April 24, 2007, 02:07 PM
I very seriously doubt if Gale McMillan poo pooed laping a barrel considering all of the barrels that came out of G. McMillan gun company in Phoenix AZ where hand lapped!! I know because i worked there for 5+ years and lapped many a barrel there. And YES!! lapping can enhance the accuracy of a barrel quite a bit if done properly!!

Rembrandt
April 24, 2007, 07:19 PM
I very seriously doubt if Gale McMillan poo pooed laping a barrel considering all of the barrels that came out of G. McMillan gun company in Phoenix AZ where hand lapped!! I know because i worked there for 5+ years and lapped many a barrel there. And YES!! lapping can enhance the accuracy of a barrel quite a bit if done properly!!

glimmerman, don't doubt what you say....here's the link in his own words, sure sounded to me like he didn't think much of barrel lapping. Has he changed on this? http://www.snipercountry.com/Articles/Barrel_BreakIn.asp

.... (What did you buy, anyhow?)
A DPMS AR15, with Leupold 6.5-20 scope, target dot.....(prairie dogs & varmints)
http://img.photobucket.com/albums/v405/Rembrandt51/ar-1.jpg

JohnBT
April 24, 2007, 08:14 PM
"I know because i worked there for 5+ years and lapped many a barrel there."

Did you lap them after they'd been crowned and chambered, or before? I'm betting before. No doubt you could lap a finished rifle, but I'd probably end up with an oversized bore on both ends of the barrel.

John

Lucky
April 24, 2007, 08:25 PM
Glimmerman; Don't worry Rembrandt is simply failing his reading comprehension test.

bigcim
April 24, 2007, 08:31 PM
Try this

http://www.cabelas.com/cabelas/en/templates/product/standard-item.jsp?id=0003181214206a&navCount=1&podId=0003181&parentId=cat20843&masterpathid=&navAction=jump&cmCat=MainCatcat602007-cat20843&catalogCode=IH&rid=&parentType=index&indexId=cat20843&hasJS=true

Rembrandt
April 24, 2007, 08:54 PM
Glimmerman; Don't worry Rembrandt is simply failing his reading comprehension test.

Lucky, you may be right. Went back and read the link twice. (My error) Doesn't appear he was opposed to barrel lapping, rather the use of JB compound afterwards. He does make a good points about the chamber and muzzle becoming larger due to the turn around pass. His comment about voiding the warranty on his barrels is what made me think he was against lapping.

So am I correct in that lapping is not for the do it yourself crowd? Only by experienced and trained personel?

USSR
April 25, 2007, 07:21 AM
So am I correct in that lapping is not for the do it yourself crowd? Only by experienced and trained personel?

That's what we've been telling you all along.

Don

glimmerman
April 25, 2007, 09:46 AM
YES!! Barrels are lapped BEFORE!! any chambering or crowning. The barrels are button rifled under sized and then lapped to correct bore dia. It takes approx. 8-10 hours to do this for each barrel(good way to build up the fore arms and bicepts. lol).

win71
April 25, 2007, 01:28 PM
If done properly as stated by glimmerman it doesn't seem you should be doing it by hand at this point. As someone else pointed out, if done too aggressively your bore may turn out to be a better hour glass than a shooter.

BigG
April 25, 2007, 02:23 PM
It sounds to me as if it is as wise an idea as serving as your own attorney.;)

I remember Mr. McMillan's participation, also. He wasn't agin it as a principle but indicated it was something handled (or not) at the factory. I would guess in some cases today, it's not handled probably by cost cutters but that doesn't mean anybody can just buy a "handy kit" and get to it. I don't think somebody without proper tooling, gauges, and knowledge should do something like take lapping compound to a barrel. It scares me. :uhoh:

I would suggest saving up and buying a better quality rifle than spending money on trying to make a silk purse out of a sow's ear. But that's just me.

Afy
April 25, 2007, 05:04 PM
So if I understood this thread correctly:

1. Buy a pre lapped barrell out of the box, guranteed by the Maker.
2. Dont waste time trying to break in a barrel..

win71
April 25, 2007, 06:13 PM
Point 1...........yes

Point 2...........you will never get a definite answer here.

Jim Watson
April 25, 2007, 06:34 PM
1. Sure, fine.

2. I don't have a McMillan barrel. If I did, I wouldn't have gone through the breaking recommended by the actual maker, Krieger. To wit:
http://www.kriegerbarrels.com/RapidCat/catalog/pagetemplate.cfm?template=/RapidCat/common/viewPage.cfm&PageId=2558&CompanyId=1246

A back breaking 13 shots for a stainless barrel. You can do that in about the time it takes to wade through one of the many threads on the subject.


Ed Harris once did a piece on lapping surplus military rifle barrels. He wasn't after mirror bright, just to knock the sharp corners off the pits so he could shoot them without endless cleaning. As I recall, he recommended casting a lead lap in the traditional manner and running it no more than 12 to 15 passes.

USSR
April 25, 2007, 08:19 PM
A back breaking 13 shots for a stainless barrel. You can do that in about the time it takes to wade through one of the many threads on the subject.

Jim,

Took me several trips to the chiropractor to get my back straightened out after breaking in my Obermeyer barrel.:D

Don

Rembrandt
April 25, 2007, 08:43 PM
Appreciate all the informative replies....I've learned a great deal.

Lucky
April 25, 2007, 10:03 PM
I just got some WS2 (tungsten disulphide) formerly sold under the brand-name 'Danzac', for the same purpose as lapping would do. Got a Mossberg ATR and if the bore might be a little rough, a nice layer of WS2 (a better lubricant that Moly in every way) will smooth it right out. And to apply it you just run it through on a patch soaked in alcohol - instead of trying to use bullets to coat the bore with it (not the best thought-out method).

atblis
April 25, 2007, 11:13 PM
YES!! Barrels are lapped BEFORE!! any chambering or crowning. The barrels are button rifled under sized and then lapped to correct bore dia. It takes approx. 8-10 hours to do this for each barrel(good way to build up the fore arms and bicepts. lol).

There's no way it takes that long to do one barrel. I would think the prices on barrels would be a touch higher if that were the case.

See how your gun shoots first!!!!

The thing about breaking in a barrel is that it doesn't really hurt the barrel to not break it in. Just start shooting, and follow good cleaning practices. Nothing special is required.

heron
April 26, 2007, 11:07 AM
I bought a new Savage Mark I FVT, and found a barrel break-in procedure recommended on Savage's website, so I did it. I can't tell you if it helps accuracy or not, but I did notice that it became much easier to clean as the process went on.
Think of it this way: since break-in consists of nothing more than shooting and cleaning, it certainly can't do any damage, and if it really does help (which I believe), then why not?
I also treated my rifle (post break-in) with Microlon Gun Juice. It now cleans almost completely with ONE wet patch after 100 rounds.
I think lapping should be left to professionals. As to fire-lapping, I read elsewhere that if you do this with a gas-operated rifle, the abrasive gets in the gas tube and destroys it in nothing flat.
Best bet: follow the manufacturer's recommendations.

glimmerman
April 26, 2007, 01:28 PM
atblis, I personally lapped several barrels at G. McMillan gun works and YES!! it does take about 8-10 hours to lap a barrel properly!!. When Gale McMillan gun works was in business his was the ONLY!! company in the world to guarantee sub 1/2 moa with properly prepared loads. And yes they where expensive rifles, the base model started at around $2300 and that was 10+ years ago. The M82 sniper in 300 win mag i built for myself when i was there will shoot 1 .30cal hole 5 shot groups all day if i do my part with my reloads.

atblis
April 26, 2007, 01:36 PM
Krieger et al. supposedly hand lap their barrels. You're telling me that someone spends 8-10 hours of labor hand lapping one of those, and I can buy one for what? $300-$400 with 8 to 10 hours of labor in it just for the hand lapping.

What kind of precision are you trying to achieve by doing this?

glimmerman
April 26, 2007, 01:45 PM
atblis, if u get a chance to see a Real!! G McMillan barrel (not the McMillan bros out there now but a real g mcmillan barrel) compare it side by side with a krieger barrel and you will se the difference instantly. A real G McMillan Barrel will cost you somewhere in the neiborhood of $800 to 1000 when they can be found. Like I said in my last post "The ONLY COMPANY IN THE WORLD THAT GUARANTEE'S 1/2 MOA with proper loads"

win71
April 26, 2007, 02:12 PM
These were some of the best barrels made at the time. I could not afford one back in the 80's and settled on a Douglas supreme which turned out to shoot almost as well. Some factory-semi custom rifles out now come close with respect to the accuracy guarantee. I have two Coopers, a .17HMR and .204 and both exceed the factory guarantee.
"22 LRs are guaranteed to shoot 1/4" 5-shot groups at 50 yards using premium grade match ammunition. 22 Hornet family cartridges are guaranteed to shoot 1/4" 3-shot groups at 50 yards using hand loads. All other centerfires are guaranteed to shoot 1/2" 3- shot groups at 100 yards using hand loaded ammunition."

atblis
April 26, 2007, 05:00 PM
Is that 800-1000 just for a barrel blank?

Do they shoot any better? Or rather measurably better (if there's a difference)? I am under the impression that the bench rest shooters would probably be the ones to note any "quality" differences in barrels, and they seem quite content with Krieger. I don't know, but I'd venture to guess that Krieger does not spend 10 hours per barrel hand lapping them.

Okay, you spend 8-10 hours lapping a barrel, do you actually get anything for your effort?

Also, before anybody flips out
I have not said McMillan barrels are crap. I am sure they're great
I have not said hand lapping doesn't do anything.
What I am questioning is a lack of optimization with regards to the law of diminishing returns. I don't find a 1/2MOA guarantee that astounding. There are plenty of smiths who offer that guarantee while using other barrels.

glimmerman
April 26, 2007, 05:39 PM
atblis, The reason everyone is shooting krieger barrels is because Gale McMillan retired back in the early 90's and sold the company to Wes Harris, who inturn brought his son into the business and needless to say his son screwed up the business so bad they went under in 99 or 2000.(he's the reason i quit!!) So G. McMillan barrels are not made anymore but do show up occaisionally. Yes a real G McMillan barrel blank will cost u $800 - 1500 depending of if they are croyo treated or heat treated and caliber. I have seen some of the 50cals go for $3500 each.

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