how wide are your nodes?

Discussion in 'Reloading' started by jmason, Aug 20, 2008.

  1. jmason

    jmason Well-Known Member

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    When you guys are developing your loads do you find your nodes in a 9/10 of a grain window or are they real narrow like 2/10?
     
  2. BENNYBOOBOO

    BENNYBOOBOO Well-Known Member

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    With the limited load testing that I have done, I have found that I can still get acceptable accuracy by going 0.3 grains above or below my node.

    For example: just worked up a load and found that my node was at 40.1 grains of H4895, outstanding accuracy. To test my load I loaded a total of 3 rounds each of 39.8, 40.1, and 40.4; shooting one round of each into three seperate 3-shot groups.

    Each group contained one round of 39.8, 40.1, and 40.4 with the result of three groups all measuring right around .5" at a 100 yard target.

    So I guess I would say that my nodes are typically around 1/2 grain wide.

    EH
     

  3. boomtube

    boomtube Well-Known Member

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    It seems somewhat dependant on the size of the case but my experience has given good accuracy from a charge variation of +-.2 to +-.5 gr.

    I've become comfortable to find the width of the node and then just drop charges in the middle. Rarely wish to weigh charges anymore, at least after load development tests.
     
  4. jmason

    jmason Well-Known Member

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    I'm still pretty new at this and the gun I'm working on now (270 win, 135smk,imr4831) seems to have a very narrow high charge node +/-.2 I was wondering if something was fishy or was that somewhat normal?
     
  5. boomtube

    boomtube Well-Known Member

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    j, I've been doing this since the mid 60s but only load for myself and a few family and friends so I'm no expert with vast experiece across the board.

    That said, your window is .4 gr wide and that seems common enough for a cartridge of that size, if the accuracy is indeed good. It's plenty wide enough that you shouldn't have to weigh each charge but with a coarse powder like 4831 I'd do it anyway.

    Try to find some H-4831SC and see if it works as well as the IMR, it sure measures better.
     
  6. jmason

    jmason Well-Known Member

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    I thought maybe the node would be a little wider. I had got .75-.9 Moa @ 200 yds on multiple sittings and ran out of that lot. Now I have a new lot which I'll try 3/10+ and 3/10- of the charge I was using in 1/10 increments. I hope the new lot doesn't give me problems. I've been working my @ss off just to get here. I've run about 150 rounds. I tried rl-22 but came up empty handed. As long as I can find this accuracy again with new lot I guess I'll move to seating depth. It's a factory gun, not a custom. Again I'm guessing here but .75-.9 moa is acceptable for a factory gun without changing the seating depth?
     
  7. summitsitter

    summitsitter Well-Known Member

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    DA question what is a node yall are talking about?
     
  8. Boss Hoss

    Boss Hoss Well-Known Member

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    NODES??????

    Sound like a personal question and I don't kiss and tell!!!!!!!!!!! lol
     
  9. jmason

    jmason Well-Known Member

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    Sweet spot in your powder charge..
     
  10. Forester

    Forester Well-Known Member

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    For a .308 sized case mine run about a half grain. If I shoot groups on either side of the middle I get accuracy almost as good but not quite. I think a wider node is always better because it allows for fluctuations in ambient temperatures and other factors.
     
  11. specweldtom

    specweldtom Well-Known Member

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    In my 7-08 with H-414, it's +- .2 grain or less. Very narrow. +- .5 grain doubles the group size. Varget appears to be slightly less sensitive, maybe +- .3 or .4 grains. Haven't shot it enough to be positive. My .30 x .378 is also surprisingly touchy. +- 1 grain of H-5010 (112 gr node) also doubles group size. Have just started experimenting with US 869. My impression is that it's not as sensitive, so I am concentrating on it.

    Plausible conclusions: different powders can give a wider or narrower accuracy charge weight range, and a 1/2 percent total variation in charge weight is too much for these 2 rifles.

    Good hunting, Tom
     
  12. MSU Marksman

    MSU Marksman Well-Known Member

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    I've always weighed every load on a beam balance scale, but I usually do load development in .5 grain increments, then fine tune up and down by .2 grain increments. For smaller rounds like a 6mmBR I’ve found +/- .2 to be pretty standard, but for larger 308 and up, +/- .5 is a reasonable number.


    In knowing this, I would be interested to see what consistency some of the higher end powder throwers get and how close to the node variations they would stay?