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Barrel Lapping....opinions?

Discussion in 'Rifle Country' started by Rembrandt, Apr 23, 2007.

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  1. Rembrandt

    Rembrandt Member

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    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 )
     
  2. USSR

    USSR Member

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    Rembrandt,

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

    Don
     
  3. DMK

    DMK Member

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  4. Rembrandt

    Rembrandt Member

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    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?
     
  5. rangerruck

    rangerruck Member

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    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?
     
  6. Jim Watson

    Jim Watson Member

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    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.
     
  7. NavyLCDR

    NavyLCDR member

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    I was wondering about fire lapping for this rifle...

    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.
     
  8. USSR

    USSR Member

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    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
     
  9. eliphalet

    eliphalet Member

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    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.
     
  10. glimmerman

    glimmerman Member

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    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!!
     
  11. Rembrandt

    Rembrandt Member

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    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

    A DPMS AR15, with Leupold 6.5-20 scope, target dot.....(prairie dogs & varmints)
    [​IMG]
     
  12. JohnBT

    JohnBT Member

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    "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
     
  13. Lucky

    Lucky Member

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    Glimmerman; Don't worry Rembrandt is simply failing his reading comprehension test.
     
  14. bigcim

    bigcim Member

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  15. Rembrandt

    Rembrandt Member

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    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?
     
  16. USSR

    USSR Member

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

    Don
     
  17. glimmerman

    glimmerman Member

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    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).
     
  18. win71

    win71 Member

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    Rembrandt

    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.
     
  19. BigG

    BigG Member

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    Home Barrel Lapping -

    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.
     
  20. Afy

    Afy Member

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    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..
     
  21. win71

    win71 Member

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    Afy

    Point 1...........yes

    Point 2...........you will never get a definite answer here.
     
  22. Jim Watson

    Jim Watson Member

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    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/Rapid...ommon/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.
     
  23. USSR

    USSR Member

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    Jim,

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

    Don
     
  24. Rembrandt

    Rembrandt Member

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    Appreciate all the informative replies....I've learned a great deal.
     
  25. Lucky

    Lucky Member

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    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).
     
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