Clean bore vs. fouled bore for 1st shot accuracy

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by WTXDrifter, Jul 5, 2012.

  1. WTXDrifter

    WTXDrifter Member

    Messages:
    18
    Joined:
    Jul 11, 2011
    Gentlemen, I have read so many articles about getting the best accuracy from a shiny clean bore and then along comes someone telling how a fouling shot gives the best. I would welcome your thoughts. not just your thoughts but also your reasoning.
     

  2. royinidaho

    royinidaho Writers Guild

    Messages:
    8,853
    Joined:
    Jan 20, 2004
    Both of my full custom rifles clean bore first shot impact is spot on. I trust them 100%

    My factory rigs are close with the clean bore first shot but I shoot at least one fouler out of them.

    I clean after ~20 rounds so its a long time between clean bore first shots.
     

  3. DDT

    DDT Member

    Messages:
    21
    Joined:
    Aug 21, 2011
    cool vid. MAY Help.

    [ame]http://youtu.be/YiDoddUL4rI[/ame]
     
  4. Mikecr

    Mikecr Well-Known Member

    Messages:
    4,246
    Joined:
    Aug 10, 2003
    I agree that a lot of it comes down to the cleanliness maintained, the lapped condition of the bore, and the stress remaining in the barrel. But these are qualifiers that can't be overlooked, or assumed away with factory barrels and common cleaning.

    I have 3 guns so far that will put a cold clean bore shot within 1/2moa accurate.
    But all 3 will do better cold -while fouled.
    All 3 will GROUP better fouled and brought up to stable temps(better than cold grouping).
    And forget cold -clean- grouping. That would suck.

    I've had other guns in the past that walk as they heat up & that throw fliers until fouled. Some of my barrels would copper foul out.
    But I've managed to take all but one of them to better 'cold pre-fouled' accuracy. The one offender, hot grouped excellent, but walked shots from cold(a T2K, tube gun).

    I agree also that carbon must be rigorously managed.
    I clean to white metal after every use, no matter how many shots fired. Then I dry pre-foul bores with tungsten disulphide(WS2)(my bullets are coated also).
    With this, I can count on my first cold pre-fouled shot being with any to follow.
    I do not agree with the assertion that copper should be left in a bore. I don't, I rarely get any copper in my bores anymore, and I just prefer it stay that way.

    Other than taking a bore to a pre-fouled state, I think you would just have to try it & see.
     
  5. WTXDrifter

    WTXDrifter Member

    Messages:
    18
    Joined:
    Jul 11, 2011
    MikeCR.

    I appreciate your timely response and now I have a few questions:

    What is Tungsten disulphide (WS2)?
    Where do I get it?
    and how is it applied?
    Are your bullets coated with the black moly?

    I'm interested in long range hunting with commercial rifles. Maybe someday I might try my hand at Class F competition.
     
  6. Bart B

    Bart B Well-Known Member

    Messages:
    2,483
    Joined:
    Dec 25, 2005
    Barrels with properly lapped smooth lands and grooves, properly stress relieved and correctly fit to receivers typically shoot within 1/4 MOA for their first through many shots up through 300 yards. At longer ranges, the slight amount of fouling that builds up from a squeaky clean bore may cause later shots to leave faster from higher pressure and therefore shoot 1/4 MOA higher at longer ranges after the first few shots.

    Factory standard barrels are not quite as smooth as high end aftermarket ones, so they often take a few shots to settle down and shoot to the same place. If they're not fit well to the receiver and/or not stress relieved good, they'll start walking shots as they get hot. Otherwise, after a few to several shots, factory barrels tend to settle down.

    Properly test your barrels with the bullets of choice and find out where it shoots with the first through 10th shot with various levels of cleaning from none to all fouling totaly removed.

    I have never used coated bullets except once on an international team in practice when one half day we used moly coated ones and the other half day shot naked ones. The naked ones shot more accurate. Shoot whatever bullets you want to.
     
  7. Mikecr

    Mikecr Well-Known Member

    Messages:
    4,246
    Joined:
    Aug 10, 2003
    You can't just 'try' coated bullets with any meaning.
    It takes a plan and management to succeed with.

    You can google tungsten disulphide. I picked up some 'technical grade' at RoseMill ~25yrs ago to begin. I doubt I've used a 1/4lb with thousands of bullets.
    Both my bullets and bores are dry coated with WS2.
    Bullets are coated as they are with moly or boron.
    My cleaned, alcohol washed, dry bores are dry burnished with a bore mop which is stored in a tube with coated BBs and a pinch of WS2 here & there.

    I suppose this powder fills bore crevices that copper would otherwise. I could fire 100rounds and manage only a single slight blue tinting of a patch. So copper is totally out of the picture with it.
    It also cleans completely out of the bore easily, and it doesn't wipe/build on itself to constriction(both unlike moly). It's slippery as pig snot, but I don't know that it affects overall velocity much(like moly). I load develop with it, calibrate my QuickLoad using it over a chrono, and I haven't seen any surprising velocities yet.

    I've donated barrels to science and found that even with WS2, if your bore finish is extreme one way or the other(polished/rough), copper fouling will still exist.
    I have fire-lapped to break-in every barrel since, factory or aftermarket alike. And I also watch with a borescope to manage their condition.

    But if you've got a good aftermarket barrel, you may not NEED to consider any of this.
     
  8. Bart B

    Bart B Well-Known Member

    Messages:
    2,483
    Joined:
    Dec 25, 2005
    That depends on the objectives, standards and conditions of the trial.
     
  9. Boss Hoss

    Boss Hoss Well-Known Member

    Messages:
    1,843
    Joined:
    Nov 10, 2005
    If you have the right Smith and using the right componets for the build there is no real change in POI between fouled or clean. I have tested this with 18 of my built rifles by one Smith. I have others that are wood built sporters by another Smith that change very little (less than .5 at 100yds) from a pristine clean condition.

    All using SMK's that are non coated.
     
  10. coyotezapper

    coyotezapper Well-Known Member

    Messages:
    678
    Joined:
    Sep 26, 2009
    Did the WS2 post clean barrel treatment for awhile but it is dirty. Now use hBN with the same process and I am 100% happy with first shot cold bore. Virtually no impact change.
     
  11. coyotezapper

    coyotezapper Well-Known Member

    Messages:
    678
    Joined:
    Sep 26, 2009

    Lower Friction

    Hex Boron Nitride (hBN) Bullet Coating

    It is important to start with clean bullets and I recommend warming them up before tumbling. WS2 and hBN process is the same.
     
  12. mtnwrunner

    mtnwrunner Well-Known Member

    Messages:
    1,135
    Joined:
    May 12, 2009
    Great question! What I can say is this----it depends on her. All my rifles are different. I don't think that you can predict one way or another--you'll just have to shoot and figure it out. I've got a 300 win mag that LOVES a dirty barrel. So, I don't let it get real dirty but I always put it away dirty and she is spot on.

    Randy
     
  13. Bart B

    Bart B Well-Known Member

    Messages:
    2,483
    Joined:
    Dec 25, 2005
    I think you can predict they'll shoot to point of aim when clean if you get one of the top quality aftermarket barrels. I predicted my 30 caliber Hart, Obermeyer and Kreiger barrels to do that; they all did. But with standard production factory barrels, I think most of them need a few shots to settle down.

    My Anschutz .22 rimfire match barrels were predicted to shoot a few MOA high with a clean barrel; they did. Same with others using Hart, Lilja and Walther rimfire match barrels; they all shot high from a clean barrel. Takes 3 or 4 shots to get them fouled enough to slow the bullets down so they shot to point of aim.
     
  14. gunner69

    gunner69 Well-Known Member

    Messages:
    157
    Joined:
    Jul 9, 2011
    Don't wreck your crown with all that bore cleaning. Use bore guides on BOTH ends of your barrel. Crown Cradle goes on the muzzle crown end.

    Home / Crown Cradle