Barrel knox bedding

Discussion in 'Gunsmithing' started by therifleman556, Jul 27, 2018.

  1. therifleman556

    therifleman556 Well-Known Member

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    When you bed a rifle, do you bed the cylindrical portion of the barrel? Or is the barrel completely free floated? Have you tried both? Which one generally works better?

    I typically bed the knox but I really don't know why.
     
  2. Dosh

    Dosh Well-Known Member

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    556, many bed just the lug and many bed beyond. A personal preference for most. A friend beds beyond and removes bedding back to tune barrels. Good luck
     
  3. ShtrRdy

    ShtrRdy Well-Known Member

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    Please forgive my ignorance, but what does " bed the knox" mean?
     
  4. 7magcreedmoor

    7magcreedmoor Well-Known Member

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    tagging in
     
  5. therifleman556

    therifleman556 Well-Known Member

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    That's just how I've heard it referred to. The cylindrical portion of the barrel I've heard called the knox form area.
     
  6. J E Custom

    J E Custom Well-Known Member

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    It's also known as the barrel shank. I generally bed a small portion (1/2" or a little more) depending on the barrel length and weight to help support the weight for the action.

    But I don't recommend bedding the shank beyond the straight part, Because it can push on the action when it heats up and change the POI.

    Some Bed about 1" of the straight shank and remove it a little at a time. this is time consuming and the results will vary, so I have found that deciding on the shank bedding length is best done up front and you will get good results without trial and error. be sure and locate the point where the shank diameter changes and stay away from it with bedding.

    Bedding a small portion of the barrel shank helps in my opinion and if done right and free float is good beyond, it helps support the action better.

    Just my opinion

    J E CUSTOM
     
  7. tinkerer

    tinkerer Well-Known Member

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    I have always bedded the barrel nut only on my Savages. Than I come back and Dremel out the nut ridges. Barrel is 100% floated.

    Larry
    Tinkerer
     
  8. Dosh

    Dosh Well-Known Member

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    Larry, fill the nut splines with modeling clay, easier than the Dremel work and less chance of a mechanical bond.
     
  9. hemiford

    hemiford Well-Known Member

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    I have one Remington project, a future project, in which I'm
    planning at the moment to have the straight portion barrel shank to be about 10~11 inches long at 1.350" diameter.
    Would there be no binding of the bedding for this whole
    length, since it's a constant diameter ?
    The barrel length will end up around 40".
     
  10. Canhunter35

    Canhunter35 Well-Known Member

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    I’m not a gun smith but I wouldn’t bed that much. I would think your stock would definitely influence your poi with that much contact
     
  11. J E Custom

    J E Custom Well-Known Member

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    Some bench rest shooters like to bed the barrel shank,and float the action and the remaining barrel.

    This works very well, but they actually bed the barrel to the stock or use a threaded sleeve in this area and bed it with screws going through the stock to hold the sleeve to the bedding. this makes the barrel harmonics and torque better because the effective floated barrel length is much shorter and it acts like a much shorter barrel reducing the whipping and torquing.

    With the action floated also, it acts like a breach plug and has very little if any effect on the rifles accuracy.

    This is a very good method for very long barrels, but it is difficult to build this way and should only be done by a smith that understands the purpose of doing it this way.

    If you go the conventional way, I don't see why it would effect the accuracy as long as the shank was turned to a true diameter all the way, and a stress free bedding was done at one time. I have personally never tried to bed that much, but I have bedded up to 3" of shank on the real heavy and long barrels with great results.

    Remember that If there is any taper in contact with the bedding, you are done when the barrel heats up and starts to grow.

    J E CUSTOM
     
  12. hemiford

    hemiford Well-Known Member

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    I have to say, I find it very hard to believe that a small
    piece of wood could bend a 1.350" bar of steel.
     
  13. tinkerer

    tinkerer Well-Known Member

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    There are several culprits, vibration and pressure. Both these can and do affect POI. The idea is to avoid and minimize the possible affects.

    Free floating avoids pressure, especially due to heating and cooling. I.e. stringing.

    Vibration, and/or barrel whip, is unpredictable. It is better to not have to contend with it. I.e. flyers.

    In a perfect world nothing changes, everything is the same shot to shot.

    The machine shooters are trying to avoid outside influences by clamping the barrel and eliminating both. More difficult in a conventional rifle. We therefore bed the action and depend on the barrel acting the same shot to shot.

    Larry
    Tinkerer
     
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  14. ShtrRdy

    ShtrRdy Well-Known Member

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    It is hard to believe, but it's true. The thing about it is that it doesn't take much deflection to have the barrel pointing slightly somewhere else on the rifle system.
     
    Last edited: Jul 29, 2018
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