Truth about Temp. Sensitive Powders

Discussion in 'Reloading' started by carriecook, Apr 14, 2014.

  1. carriecook

    carriecook New Member

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    So used to be a member here a long time ago, but things happened and I'm back with questions. I've been handloading now for years, and I have always used IMR 4895 for all my loads and calibers from .223 to .308 to 6.5x55. 7.5x55, 30-06, and 7.62x54R. I've won gold at the CMP nationals with it as well as every other color of medal. I also shoot long range very often and have modern rifles for the task.

    I come here today with a question about the relevance of the 'extreme' powders that are available now and have been for a while. I've used Benchmark and Varget and found both to be of poor lot-to-lot quality and neither display the so called temperature insensitivity that is claimed by the manufacturer. Having used all three powders in all of the above cartridges (with a few exceptions), I had the best results across a spectrum of temperatures with IMR 4895. So what's the deal with that?

    I am beginning to think that, based on my testing and the results I have gathered, that there is no such thing as a temperature insensitive powder. I may go so far as to say that the results on the hodgdon website are just marketing hype and that there isn't really a difference at all.

    has anyone else had this experience with these powders? I am very curious to hear what you have to say about this, people of the internet.
     
  2. MudRunner2005

    MudRunner2005 Well-Known Member

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    I've always had consistency with Varget.

    H1000 on the other hand, I have first-hand witnessed poor lot-to-lot consistency, and temperature inconsistency out of the SAME loads I made up during the wintertime that shot good for me, and during the summer they were all over the place, and have had the opposite happen with loads developed during the summer not being consistent during the winter...

    Since then, I have swapped to using IMR 7828 SSC for allmost all of my long-action & magnum rifle calibers, and having excellent success. I also use Varget for my .308 and 7mm-08. And I still have a few of the Alliant Reloder powders I use for a few calibers that I worked up really good loads for, and for fire-forming brass.
     
  3. Marble

    Marble Well-Known Member

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    I was told by an old timer to try a few things:

    1. Put a small amount of your ammo you want to shoot in the freezer overnight. When you go to the range, put ice on the bottom of an ice chest with a barrier, probably cardboard, and your box of shells. When you go to the range, keep them in the ice chest and shoot one at a time. Record velocities.

    2. Have one box sitting out as normal. Record velocities.

    3. Put another in your truck in the warm summer heat and let them get warm, not hot. Record velocities.


    Crazy idea? It's not scientific, but I could probably record temperatures and do a write up if anyone is interested.
     
  4. Twodogs10mm

    Twodogs10mm Well-Known Member

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    Tag
     
  5. MudRunner2005

    MudRunner2005 Well-Known Member

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    I would enjoy the read, and look forward to seeing your results, if you test Varget, H1000, Reloder 22, 7828 SSC, and some others powders of that sort.
     
  6. Barrelnut

    Barrelnut Well-Known Member

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    Will hopefully try Marble's tests tomorrow on RL-17. Been wanting to do it a while. So now's a good a time as any I guess.
     
  7. Korhil78

    Korhil78 Well-Known Member

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    Tagging...this will be interesting. I will try it with H1000 in a few weeks and post the results.
     
  8. chad

    chad Well-Known Member

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    I am very interested in this. I have reloader 17 and I am looking for 7828ssc for load development in my new 280AI.

    When it was a 280 I used reloader19. if it was cold weather it would shoot one hole. when it would warm up I couldn't hit a pop can at a 100 yards.

    I have heard good things about 7828ssc and reloader 17 so I will be reading the tests you fellers post up.
     
  9. MMERSS

    MMERSS Well-Known Member

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    Welcome back!

    Powder temper variance causing change to an average muzzle velocity may not be as much of a concern shooting competition as for those shooting first round cold bore while hunting. A 40 fps swing one way or the other during competition can be corrected within the first few sighter shots. Not accounting for an average velocity change can be detrimental with the success of a LR or ELR hunt.

    All powders are temperature sensitive, some more than others. Take advertising with a “grain of salt” and confirm with real results. One can reference Nosler about "truth about their claimed LRAB G1 BC numbers." As stated with lot-to-lot inconsistency with certain powders the same approach should be taken with powder temperatures and the effects on ballistics, that being shooting in varying conditions to confirm precision potential and velocities. Having a power producing less change to average velocity with an increase or decrease in temperature is important to a hunter when not accounting for this change in a ballistics solution.

    One good practice is control what you can. I was placing my ammo in coolers during the Camp Perry Nationals back in the 80’s. I was young but understood the importance of not shooting ammo with temperatures in the mid 90’s when I usually shot the ammo during much cooler temperatures during off mid summer afternoons. For LR to ELR hunting same principal applies. Conduct ballistics validation near temperatures expected to be encountered during hunting season. When hunting, place your ammo inside a pocket when the temperature is significantly cooler outside. Drop your Kestrel in the pocket to monitor the temperature. If the temp is too cold, move the ammo to your inside shirt pocket. If the temp is too warm move the ammo to a pocket further away from your body or place the ammo back into the gun.

    As long as precision holds, muzzle velocity change due to powder temperature variance can be accounted for both in ballistics solutions and competition sighters. The problem arises with unconfirmed effects of precision and velocities not accounted for due to temperature change with certain powders.
     
  10. MudRunner2005

    MudRunner2005 Well-Known Member

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    Those are on 2 different ends of the spectrum. 17 is a fast burner, and 7828 SSC is a slow burner that builds huge pressure and gives insane velocities. Be careful working up with it. Pressure signs can pop up before you know it.

    I use it in my .25-06 AI and .30-06 AI as well as a bunch of other calibers, with great results.
     
  11. Buckinrut25

    Buckinrut25 Active Member

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    Im deffinatly going to try this. I have some loaded I need to test with imr 4350 I will be shooting soon. 7mm mag 162 sst 60gr imr 4350 26in tube. I'll post my results.
     
  12. bbutturff

    bbutturff Well-Known Member

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    Tagged
     
  13. Marble

    Marble Well-Known Member

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    I can do RL15, RL22, IMR4350, H4350 and Retumbo. I don't think I have any others.

    I'm waiting for a few supplies and I'll test what I can and report back. Probably a month or so.
     
  14. Greyfox

    Greyfox Well-Known Member

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    I have had experience with a few powders when dealing with temperature extremes. Using IMR4350 and IMR7828 in temperatures ranging from 20-80 degrees I noted velocity and POI differences of +30 FPS and a few inches at 500 yards. This was the typical variation over a few years using my 270 WSM. Using my 6.5x284 and 300WM rifles with Extreme Retumbo and H4831sc, velocity and POI differences were basically very slight to non existent over the same temperature range. I don't claim my experience to be very scientific, but it's good enough for me to buy into the improved temperature insensitivity of the exteme Hodgdon powders.