Temperature testing for different powders

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  • badmoon692008
    Bloodstained
    • Mar 2015
    • 79

    Temperature testing for different powders

    I know there has been lots of discussion on how much temperature changes can affect different powders, and it seems like the only ones that can handle it relatively well are the Hodgdon "Extreme" line (feel free to correct me if there are others)
    Now I'm assuming this change has more to do with the actual temperature of the case and powder than ambient air (considering ambient air really doesn't have anything to do with the reaction for the most part). With that being said, has anyone ever tried a single sitting test to see how different powders react to different temps? Load up 3 sets of each load with as many different powders as you have, keep one set in a cooler or a refrigerator (down to maybe 0F to approximate winter hunting), one at ambient temp, and then one in direct sunlight, maybe even in a controllable toaster oven or something up to 100+F to approximate summer hunting/hunting somewhere warm.
    Once you stabilize the temperature of the rounds remove them one by one and shoot them through a chrono to measure the difference in velocities?

    Or even to make is a little more simple, if you know you're developing a hunting load, and it's always between 0F and 20F for your hunting season, develop the load and then test your final work up while holding the round at that temp before test firing.

    Will the gun being a different temperature skew the results too much?
    Does this seem like a reasonable way to approximate the changes from temp?
    Has this been done before and I just need to get better at looking?
  • LRRPF52
    Super Moderator
    • Sep 2014
    • 8569

    #2
    Many of the Vihtavuori extruded powders are also great at being insensitive to temp changes. Most extruded powders seem to do well in this regard due to the geometry.

    Yes, people have done temp sensitivity testing in the manner you describe with a cooler full of ice. Several have done it here on the forum.
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    • Adam Lilja
      Warrior
      • Dec 2013
      • 267

      #3
      Some gunpowder has the reputation of being susceptible to variations in temperature, while others are purposely designed to be stable in extremes of heat and cold


      Lots of articles on this subject

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      • sneaky one
        Chieftain
        • Mar 2011
        • 3077

        #4
        I have had no drama in all the powders I use- during the hot -cold sinks . Testing from cold to hot. Really?

        If anyone else has some data- let it rock.

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        • kmon
          Chieftain
          • Feb 2015
          • 2095

          #5
          7mm-08 with Varget and 140gr Ballistic tips there was a 35fps difference between temps of 24 degrees and 98 degrees, same batch of reloads, rifle and chrono. With the load I had been using it was almost 100fps difference. That was shortly after Varget was introduced that I tried it.

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          • sneaky one
            Chieftain
            • Mar 2011
            • 3077

            #6
            Yes kmon- for a standard range that most hunt inside of- 20-300 yds,. The effect would be small, as a drift point , from initial zero at a controlled temp . Up , or down the scale.

            It's adaptable to - make a chart for your scope- mini sized..

            I had fun testing all this for the last 2 years, and ,,, lighter pills- all at the same time.

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