Same Powder Different Lot ??(Please read)

Discussion in 'Long Range Hunting & Shooting' started by bigbuck, Nov 8, 2012.

  1. bigbuck

    bigbuck Well-Known Member

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    Last time I had shot long range was during the summer. I have all of my data recorded.

    Rifle 300 RUM

    Powder retumbo
    Primer Fed 215M
    210 Berger .
    MV 2900 FPS
    Now for my questions:)

    1. I bought a new pound of Retumbo powder so what should I expect when I run the same MV into my ballistics soft ware, this being a different Lot ?

    2. What about the Temp. change ? It will be colder when I try and shoot tomorrow than when I was shooting back in the summer ?

    I will have all of my answers tomorrow but I just wnated to hear your experience .

    Thanks for taking the time to read ...........,
     
  2. SBruce

    SBruce Well-Known Member

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    I haven't yet changed lot#'s with Retumbo, cause I bought 8#. I don't know what to expect when I change lots the first time either.
    Interested to read what comes of this.
     

  3. barnesuser28

    barnesuser28 Well-Known Member

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    i changed lots of retumbo in the 338 Lapua and had to go from 84.4 grains to 82.4 grains to get back to were there werent ejector marks and i got accuracy back. My velocity dropped 150 fps.
     
  4. nddodd

    nddodd Well-Known Member

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    There was a thread 3-4 years ago on here about this same thing on the same powder and the same thing happened new lot was hotter by a couple grains. That's why I always buy 8lb jugs, I know that doesn't help you much but if your gun likes retumbo buy 8lbs and drop down a couple grains and work your way up and hopefully you'll keep your velocity before pressure hits.


    Nathan
     
  5. backwoods83

    backwoods83 Well-Known Member

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    If your old lot of Retumbo has a lot# of 5026 or lower it is the right burn rate, if the lot# is 5027-5098 your velocity will likely be higher or be the same with more pressure, I found this out in my 6.5x284, had to back off 1.5 grns and lost 30fps, so I went to another suplier and got a bunch of the older lot. The powder between the lot numbers I mentioned is closer to H1000 than Retumbo, about on par with RL25.
     
  6. JeffVN

    JeffVN Well-Known Member

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    +1 find a lot that your rifle likes and buy 8# jugs, more than one if you can. The lot-to-lot variance is not isolated to Retumbo or H1000, but is also true for RL-25 (the three powders that I am most familiar with). When I get new jugs, I run them over the chronograph to match the needed velocity, if I can. I recall a major lot-to-lot variance problem with Varget a few years back also.

    Jeffvn
     
  7. bigbuck

    bigbuck Well-Known Member

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    Thanks for the replies. my impacts where high at 556 yards today .
     
  8. brentc

    brentc Well-Known Member

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    I just bought 5 lbs of 5026 made in December 2011. I hope it's similar to what I have been using.
     
  9. moombaskier

    moombaskier Well-Known Member

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    I can't imagine only buying 1lb. of Retumbo for a 300RUM. For your bullet weight it's just about the best pick and if it has worked in the past do yourself a favor and buy it 8lbs at a time. You would also be better off to buy enough of your 210's in the same lot# to launch with that 8lbs. The Berger's can vary quite a bit from lot to lot too.
     
  10. backwoods83

    backwoods83 Well-Known Member

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    Brentc, I have a pound of 5026 lot# it is the same as my recent 3lbs of 4986 lot, its where it should be in my rifle.
     
  11. Cornfield Flats

    Cornfield Flats Active Member

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    A person can't get away without chronographing loads with a new powder lot.
     
  12. bigbuck

    bigbuck Well-Known Member

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    I have a CDM 2 I didnt chrono this new powder because I have found my chrony to say one thing and my actual field impact shows different . I would start with a chrony then let the software match my real world data as far as impacts on my target . I thought I would be close enough then select the target validation mode and go from there. just my opinion.
     
  13. meat head

    meat head Well-Known Member

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    this may sound stupid as long as i have reloaded but where is the lot num. on the h1000 one can has a num. the other one doesn"t thanksgun)
     
  14. Dr. Vette

    Dr. Vette Well-Known Member

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    Here you go.
    5023 is the lot number on this one.
     

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