hbn or other ways for stoping cold welding(or whatever it is called)?

Discussion in 'Reloading' started by big_matt_duq, Nov 3, 2018.

  1. big_matt_duq

    big_matt_duq Well-Known Member

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    I tend to load large batches of hunting ammo and may not shoot it all in a year or two. After reading about how the dissimilar metals react over time and causing pressure/velocity spikes I have been thinking about how to minimize it. I do try to leave a bit of imperial sizing wax in the necks and have quit wet tumbling my brass to leave a bit of carbon. I believe I have seen the cold weld issue on my 223 ai fireform loads but usually chalked it up to fireforming. I am thinking about loading a few batches of hunting ammo for some rifles and they need new loads worked up as well so I figured now would be the best time to experiment with HBN if it has benefits. I like the claims of better cold bore consistency but really I am just looking to improve the shelf life of my reloads. The other question I have is am I overthinking this?
     
  2. rfurman24

    rfurman24 Well-Known Member

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    Broz has reported that HBN fixes the issue you are referring to. I rarely have ammo sitting around long enough to test this.
     
  3. eklarsen

    eklarsen Well-Known Member

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    You are not overthinking it. HBN will help exactly the issue you are talking about but will also lower friction so you may need to redo your load testing, typically you may need to add a couple grains more powder to keep velocity the same as non HBN coated bullets.
    I personally use HBN coated bullets on my long range\accuracy guns but do not on my plinkers.
     
  4. jsthntn247

    jsthntn247 Well-Known Member

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    Get some liquid spray graphite and put it in the necks with a a tip. They won’t cold weld anymore.
     
  5. MagnumManiac

    MagnumManiac Well-Known Member

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    Many moons ago I had the same issue. I would steel wool (0000) my necks prior to seating. Even using light tension (.0015”) after a year or two pressures would spike.

    When I started F-Class, an old timer asked if I ran graphite or mica in my necks or if I left them dirty. I told him I cleaned the necks on ALL of my ammo.
    He said that was bad for consistent neck tension, so I stopped doing it and followed his procedures. Not only did my ES/SD lower but my groups tightened even more, which I thought I had got them as small as I could.

    So, ever since, either using a mandrel or a size button, which I do with Forster honed neck FL dies, I run powdered graphite (real fine) on a brush sparily through the neck, I find a little goes a long way and I NEVER get cold welding of my bullets.

    Cheers.
    :D
     
  6. The Oregonian

    The Oregonian Well-Known Member

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    How much impact on your ES/SD and grouping did you see?
     
  7. MagnumManiac

    MagnumManiac Well-Known Member

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    SD, which was in the teens, was halved. Goups went from 3/8MoA into genuine 1/4MoA @ 300mtrs.
    Prior to this, I had NEVER got single digit SD’s, I thought that was the best I could do.

    Cheers.
    :D
     
  8. trueblue

    trueblue Well-Known Member

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    Is that something like motor mica?
    One thing I will do to break the bond is reseat the bullet by .001 with a ultra micrometer seater it is easy, and does not affect my longrange accuracy.
     
  9. big_matt_duq

    big_matt_duq Well-Known Member

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    So are you just putting it on a brush and running it through the the necks right before dumping powder and seating the bullet?
     
  10. bigedp51

    bigedp51 Well-Known Member

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    If you Google powdered graphite you will find it is nothing more than finely ground carbon, And if you tumble your brass clean dipping your case necks in graphite will replace the missing carbon in your case necks.

    [​IMG]
     
  11. MagnumManiac

    MagnumManiac Well-Known Member

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    Yep, exactly what I do.
    I used to seat my bullets long, maybe a week or two prior to a match, then final seat at the range when I got there.
    The above method means that I can seat whenever or however I want and not worry about pressure spiking.
    I pulled some seated comp rounds and they felt exactly the same a year later as they did the day I loaded them.

    The mica I used was insulation flaked mica that was ground up into a powder, what other uses it has I am unsure of.

    Cheers.
    ;)
     
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  12. Rstrick0352

    Rstrick0352 New Member

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    How quickly have some of you experienced this occurring? I feel like this has occurred to me in a matter of months, maybe even a couple weeks or less, or I could just be misdiagnosing...
     
  13. MagnumManiac

    MagnumManiac Well-Known Member

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    With a squeaky clean neck, it has occurred in less than a month for me. That was why I seated long and final seated at the match.

    Cheers.
    :(
     
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  14. Rstrick0352

    Rstrick0352 New Member

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    Thanks! Finally something to go off of. I SS wet tumble so I’m certain this has been my issue.