warm bbl walking shots left

Discussion in 'General Rifle Discussion' started by cornbelt, Feb 14, 2011.

  1. cornbelt

    cornbelt New Member

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    What causes a bull bbl to walk the shots to the left? Its free floated and a Douglas. So did I do something cleverly stupid when I put it together?:confused:
     
  2. Dillinger

    Dillinger New Member

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    First off, Welcome to the FTF Community. Several of the existing members would like you to stop by the Introductions section and tell us a little about yourself. I will leave that up to you.

    You have discovered why the skillset of "Sniper" is a whole 'nother level of marksmanship.

    Your initial shot is Cold Bore. That is what the weapon will do straight out of the gun sleeve.

    After you put a few rounds down the barrel it is normal for the Point of Impact to be different than your initial Cold Bore shot due to the barrel warming and the barrel becoming dirty with use.

    It has to do with harmonics, heat, accumulation of gunpowder in the barrel and a bunch of stuff that is WAY over my head. :eek:

    I don't think you did anything wrong unless you are seeing a SERIOUS change in impact after the barrel warms.

    Can we get some specs here??

    JD
     

  3. cornbelt

    cornbelt New Member

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    '98 Mauser .22/.250 . At 25 yds shots will walk off to the left more or less an inch per shot. After it cools, it starts all over again from zero.
     
  4. Dillinger

    Dillinger New Member

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    So you have a total of an inch or so of walk when it warms up? This is no big deal.

    Or you have it walking an inch PER SHOT as it warms up?? :eek:
     
  5. cornbelt

    cornbelt New Member

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    Yep! One inch per shot. I don't think I've shot it more than 5 shots before letting it cool, so I don't know if it would quit after a while, but I'd run out of target.
     
  6. JTJ

    JTJ Well-Known Member Supporter

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    I had a Ruger 77 270 sporter that climbed with each shot. Ruger put pressure on the barrel at the front of the stock on purpose. I had the barrel floated and no more climbing. It was sub moa after the float. I am not an expert by any means but if the barrel is floated and climbing left and high, I would suspect a problem in the action bedding or a bad barrel.
     
  7. cornbelt

    cornbelt New Member

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    Action is all bedded. No pillars used; just the lug under the large ring. The other rifles haven't done this, but I have more faith in Douglas than in myself, so maybe the bbl is good and I'm not, but durned if I can figure out what I did wrong.
    It only goes left and not high. Would that have anything to do with the cast-off? (3/8")
     
  8. Dillinger

    Dillinger New Member

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    Cornbelt - Optics or Iron Sights?

    Any chances your sights are loose??

    Probably not because you said it works it's way back to zero when cooled.

    I am thinking there is something with tension on the action versus stock that is heat induced. :confused:

    I'll PM stalkingbear, he has been doing this sort of thing for like 27 years and when he talks, I read and learn.

    More to follow.

    JD
     
  9. M14sRock

    M14sRock New Member

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    Cornbelt, not all barrels like to be free floated. Is this a thin contour barrel?

    Have you tried shimming? Placing thin pieces of aluminum or cardboard between the end of the forend and the barrel? Try a few dif thicknesses.

    I'm assuming your action screws are properly torqued?
     
  10. USEBOTHHANDS

    USEBOTHHANDS New Member

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    how many shots does it take to "plane out" so to speak? what i mean to say is, does it continue walking until it is off the paper, or will it get to a point, and start grouping?
     
  11. masterPsmith

    masterPsmith New Member

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    He stated that it is a bull barrel and it is free floated and the action is bedded. What I would gather from what it is doing, is that either the barrel shoulder is not square with the action (having a very slight gap on one side), or the barrel was never stress relieved after machining and straightening. If the barrel had to be straightened after final machining and was not stress relieved afterwards, it will cause it to walk the shots when it heats up as he describes and will return to zero when it cools.


    Jim.................
     
  12. stalkingbear

    stalkingbear Well-Known Member

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    Are you SURE the barrel is free floated enough? If there's ever an instance where cyrogenically freezing/stress relief will work, this is a classic example. The barrel wasn't stress relieved fully/properly and is walking as it warms up. If it was the bedding, it wouldn't return to zero for cold bore shots. If i was you I'd have it cyroed and I'm positive that'll take care of most of your problem. Having it cyroed isn't that expensive either.
     
  13. cornbelt

    cornbelt New Member

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    Receiver face was trued, as was the mating surface of the bbl; dialed in on the bore. The scope mounts were put on with a Forster jig. And I've run stuff the length of the forearm and not touched until about 2" from the reciever ring.
    So , if I take the action plumb out and shoot it, that ought to tell me whether or not its a stock issue, eh?
    And what if I go the cyro route? Who does it? And what's the ballpark on the cost?
     
  14. stalkingbear

    stalkingbear Well-Known Member

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  15. Dillinger

    Dillinger New Member

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    We have used ONE CRYO on "Old Military Road" in Puyallup, Wa. and they have never treated us poorly.

    Cryogenics is most commonly used on softball bats, but we have had actions ( Pre-'64 Winchester Model 70 specifically as it makes it easier on tooling ) and very few barrels, always by request, done there.

    They do great work and we have never had a problem with not getting what we have requested. (we have had a problem with timelines as their calendar as opposed to ours. :eek:)

    If you are going to go the Cryo route, I can recommend One Cryo based on personal interacton with them.

    JD
     
  16. M14sRock

    M14sRock New Member

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    Actually Jim, he did not state that the barrel is a bull barrel. Did I miss that?
     
  17. USEBOTHHANDS

    USEBOTHHANDS New Member

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    i believe this is what you'd be looking for.
     
  18. M14sRock

    M14sRock New Member

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    Haha!!! OH! You meant THAT bull barrel?
     
  19. cornbelt

    cornbelt New Member

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    Thanks for the sources for cyro. Sounds like I'd better be contacting one of them well ahead of time (like before watermelon season).
    By the way, Both Hands, I don't know how far it would walk. I always quit when it ran out of paper. With a cold bbl though, it'll put them in the same hole.
     
  20. USEBOTHHANDS

    USEBOTHHANDS New Member

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    so it just kept walking......................ewwwww!:(

    all the opinions (and hypothesis) are great, but without looking at the rifle and shooting it, that's all they are "educated guesses."

    if you can, before you spend any money (and are maybe told that you have to do this, this, AND this to fix the problem), see if you can't find a reputable gunsmith, have him shoot it, and tell you what he thinks can/should be done for it. if he thinks he can fix it (STRIKE THAT, KNOWS HE CAN FIX IT), MAKE SURE YOU GET IT IN WRITING, ALONG WITH THE CLAUSES: 1. IF HE DOESN'T FIX THE PROBLEM, YOU DON'T PAY FOR IT, 2. HE PAYS FOR IT IF HE "BREAKS" IT.

    "if a tire goes flat, it's cheaper to patch it (and be as it should be) as opposed to getting it re-treaded." ya know?
     
    Last edited: Feb 16, 2011