Pressure test ladder - how do I do it

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by jfseaman, Aug 23, 2014.

  1. jfseaman

    jfseaman Well-Known Member

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    My 338/26-Nosler should be done any day now.

    I have my MagnetoSpeed V2 and a Pressure Trace II.

    I want to do some pressure measurements to document actuals for powder+bullet combinations.

    Does anyone have a ladder format for this?
     
  2. Mikecr

    Mikecr Well-Known Member

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    What do you want to do?
     

  3. jfseaman

    jfseaman Well-Known Member

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    I what to publish numbers that I have confidence in.

    Say I find that the max load produces 2850fps with xxx bullet at yyy COAL, what is that pressure really?

    So, I'm looking for input on methodology.

    I could:
    Make one load of 3 rounds and validate predictions vs actual.
    Make 1 round from the predicted minimum to maximum and run the series. Validate that against the model.

    Then run 3 rounds of min and 3 of max to double check.

    Is that the best or most 'normal' method for producing pressure ladders?
     
  4. FearNoWind

    FearNoWind Well-Known Member

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    I'm not sure how you would apply the ladder test principal to your objective but you can read everything about ladder testing at:
    Long-Range Load Development
    To obtain meaningful results you'll need a lead sled or a similar type of rest.
     
  5. MagnumManiac

    MagnumManiac Well-Known Member

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    I don't really understand want you want to do, maybe comparison to quick load is your aim?
    What model are you referring to?

    Anyway, I have a Pressure Trace II, the numbers it supplies are absolute pressure, no fudge factors or subtracting a form factor for discrepency to reference ammo.
    I tried the factory ammo comparison, but found it was well down from SAAMI spec in all rifles tested.
    These days when I start testing a new bullet/powder combo, I just test for pressure and whatever it spits out I accept as being whatever. I load one round for each powder weight and test.
    I don't average anything out, just shoot and what is, is.

    Cheers.
    gun)
     
    Last edited: Aug 25, 2014
  6. jfseaman

    jfseaman Well-Known Member

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    That's the kind of thing I'm looking for.