temperature sensitive powders

Discussion in 'Long Range Hunting & Shooting' started by supercrossbmx69, Feb 2, 2011.

  1. supercrossbmx69

    supercrossbmx69 Well-Known Member

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    Dec 31, 2010
    i hunt in montana so i shoot my rifles during the summer mostly when its rather warm but by the time hunting season comes around its normally from 40-5 degrees so im wondering if anyone has tryed putting theyre ammo inside theyre clothing against theyre body to keep it at a warmer temperature and if it would shoot like normal or is the barrel affected by temp. as well? thanks
     
  2. liltank

    liltank Well-Known Member

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    The two biggest changes to ballistics is temperature and elevation. Elevation determines the distance that you can shoot carrying enough energy. The higher you go, the farther you can shoot.

    Temperature effects ballistics a little more in my opinion. Depending on the powder you can see 100+fps variable (more prone in ball powders) that will definitely change your original zero. Keeping them warm will help with keeping them as close to a summer time ballistics. Just make sure you squeeze it off as quick as you can. There are some powders that are a little less effected by the temps. A lot of the Hodgdon extreme powders (Varget, H series, IMR4064) are suppose to be able to handle temperature change. I know that Snipers shooting M118LR expect 2700fps in the summer and 2650 in the winter. They have this stuff logged and can adjust accordingly.

    So to wrap this up, if you want to store them in your pocket, its not going to hurt anything. Make sure it is an internal pocket, the only problem I see, is that if you have to make a quick shot you will need to load a round and by that time you may have missed an opportunity. My suggestion would be to get out and see what it is really doing in the winter months and record your results to adjust accordingly.

    Tank
     

  3. J E Custom

    J E Custom Well-Known Member

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    The ammo is more effected by the cold than the barrel.

    Work up a winter load or go to one of the Extreme powders by Hodgdon.

    You can keep the ammo in your clothing and just before making the shot load it
    in the chamber but you cant leave it in there very long before the barrel cools it
    down (A few minutes).

    J E CUSTOM
     
  4. ubettcha13

    ubettcha13 Well-Known Member

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    Aug 22, 2010
    Try testing in the temps your going to see while hunting. In standard cartidges sometimes using a mag primer will give you the same numbers as you got in summer. The Hodgdon extreme powders help alot as stated.
    The best case is getting dope and recording it. I have used a hard foam sheet you buy at a building supply house for a mat. On top of that an old army wool blanket. For clothes I add insulated coveralls over what the temps call for. The extra warmth from the coveralls allow me to stay put for extended periods as well as better concentration. The only distance hunting I do is this time of yr for song dogs I've seen -35 and it sux but it is also the best time to go.
    LED read outs don't work well in super cold conditions so you may have to calculate through known drops as to what your load is doing at excessively cold temps.