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Pushing it too far?

Discussion in '10mm Reloading Forum' started by jon1977, Jan 15, 2011.


  1. jon1977

    jon1977
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    I have been working uo a maximum load load for the 10mm. I am using a stock G20, 180 grain bullets, and 800x.
    I startyed at 8.5 grains, the listed max, and worked up in .5 grain increments. I am up to 11.0 grainswith 800x and 180 grain tmj with no pressure signs. I only fired three rounds as I know I am way over max. I was just trying to see at what level I would see signs of excess pressure and I have not yet. I am not going to go any higher, just wanted to know what you guys think.

    Thanks, Jon
     

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  2. MinervaDoe

    MinervaDoe
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    I think your judgement is questionable.
    No signs of excess pressure? Like what, missing fingers?
     

  3. jon1977

    jon1977
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    no flattened primers, no brass bulging. I know its not smart to load ;past max loads but I have been loading for 15 years without incident.
     
  4. MinervaDoe

    MinervaDoe
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    I was going to ask about the primers. I'm surprised.
    When you put a mcrometer on the case and compare it to rounds fired within SAAMI spec., what difference do you measure?
     
  5. jon1977

    jon1977
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    I was suprised with the primers as well. The spec case measures 0.981 and the hot case measures 0.983....strange.
     
  6. MinervaDoe

    MinervaDoe
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    In Ken Waters Pet Loads, he gives some techniques that us ordinary mortals can use to determine excessive pressure.
    He measures the diameter of what he calls the pressure ring (the case right above the rim, which is the first place that you will see a case blowout, or case separation).
    http://www.amazon.com/Pet-Loads-Com...=sr_1_1?ie=UTF8&s=books&qid=1295144418&sr=1-1

    He compares factory ammo to reloads. He describes an increase on the pressure ring of 1/2 a thousandth (.0005) (over fired factory ammo) as a sign of excessive pressure.

    I make a point of only using published loads (and even then, I've been skeptical of several of those being safe). My first reloading manual was a Speer #11 and I occassionally find a load in this manual which far exceeds any other load that I can find today.
    It won't be long before someone comes along and chimes in on this thread with words encouraging you to continue. Exercise caution, the gun may fail before the case does.
     
    #6 MinervaDoe, Jan 15, 2011
    Last edited: Jan 15, 2011
  7. jon1977

    jon1977
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    Thanks for your help, I think I am going to pull them and back them down....no sense in hurting my gun or possibly myself.
     
  8. MinervaDoe

    MinervaDoe
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    If you have a chronograph, Waters had another interesting way of judging excesive pressure.
    For every grain that you increase your powder (within normal range) you should be able to calculate what the increase in FPS will be. Once this increase in FPS becomes less, you are entering the realm of excess pressure (and besides, why go any higher once you have diminishing returns).
     
  9. Bringsteen

    Bringsteen
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    10mm Shooter

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    I'd like to know the numbers you're putting up.

    I respect the caution others are registering. But I am the kind of person willing to test ultra-hot loads wearing a motorcycle helmet and welder's gloves, so I respect your intrepidity.
     
  10. nickE10mm

    nickE10mm
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    F.S.F.O.S.

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    Watching this thread now ...

    (btw Jon, you need to measure the case head DIAMETER, not the case length) ... .99x is a case length.... MinervaDoe was referring to measuring the case head DIAMETER which will be in the .42xx range I believe.

    ;)
     
    #10 nickE10mm, Jan 16, 2011
    Last edited: Jan 16, 2011
  11. DWARREN123

    DWARREN123
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    If you are going to do it then IMR 800-X is probably the powder to do it with.
    Be careful and have fun. :supergrin: