OCW Method

Discussion in 'Long Range Hunting & Shooting' started by CWM-RHG, Aug 18, 2019.


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  1. CWM-RHG

    CWM-RHG Previously Chuck Moles

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    I apologize if I seem ignorant with this post but with the OCW method, either adjusting the powder charges or changing the jumps should give you to find the sweet spot, correct? Its all about getting the bullet to exit the barrel at "right, same" time. Also, inconsistent velocities (say an ES of 25) would make finding the sweet spot even more difficult because in theory the bullet should be leaving the barrel at different times due to the speed variation.
     
  2. ShtrRdy

    ShtrRdy Well-Known Member

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    I think you basically have the right idea. Optimal Charge Weight deals with different amounts of powder charges in a sequentially increasing load. I usually use 0.3 to 0.4 grain steps. You then fire then into separate 3 to 5 shot groups. After firing compare the location of the the group to the adjacent charge weight group. This will give you an idea of what powder charge weight causes the bullet to exit the barrel at the same point in the barrel vibration cycle.
     
  3. CWM-RHG

    CWM-RHG Previously Chuck Moles

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    Thank you....
     
  4. ShtrRdy

    ShtrRdy Well-Known Member

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  5. Varmint Hunter

    Varmint Hunter Well-Known Member

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    IME - if you repeat the exact same OCW test more than once you will often get different results.
    This is worth consideration before investing too much effort in perfecting what looks like a promising charge weight based on a single OCW test result.
    Just my 2 cents.
     
  6. ShtrRdy

    ShtrRdy Well-Known Member

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    I'm curious - what method / approach do you use for load development?

    Thanks -- Todd
     
  7. Varmint Hunter

    Varmint Hunter Well-Known Member

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    I typically use a very unscientific approach. I review several reloading manuals, in print and on-line, for powders that have proven to work well in other rifles. While working up from a minimum charge to a (listed) maximum charge I look for accuracy and signs of excess pressure. If I find a good load that appears well within normal pressure limits I start to vary bullet seating depths to see if group size can be further reduced. I shoot all loads over a Oehler 35P and keep records of velocity and standard deviation.

    If no charge seems to stand out as being potentially accurate then I just switch to another powder and start over.

    I have also tried switching brass and primers to develop the best load but that has rarely been productive. The vast majority of my handloads are in Lapua cases with Federal match primers.

    FWIW - I tried the OCW method on several occasions and found that results were often hard to duplicate. Thus, making it difficult to make valid conclusions from their results. Based on all that I've read on the internet, others have had different (more conclusive) results with the OCW method than I have.
     
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