Chronographing brass

Discussion in 'The Basics, Starting Out' started by ReDnEcKBoHuNtEr, Jun 22, 2010.

  1. ReDnEcKBoHuNtEr

    ReDnEcKBoHuNtEr Member

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    I bought a chrono the other day and loaded up my 35 gr VARGET with a 55 grain bullet and cci primers(for my 22-250). i trickled the powder and the biggest difference was .1 (35 gr compared to 35.1)...i used all the same REMINGTON casings

    when i shot it through the chrono i was getting different readings... i shot 5 shots and they went from 3599-3626....is that going to be a problem. i really only want to have an accurate drop chart out to 500 yards as i am also working on a 7mm-08 project. Is there something i did wrong to get different readings or is that 27 fps difference not going to be a problem when shooting at 500 yards
     
  2. jeffro

    jeffro Well-Known Member

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    27fps spread is not that bad, even though it would be better if you could find a load that had less of a spread.
     

  3. ReDnEcKBoHuNtEr

    ReDnEcKBoHuNtEr Member

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    so you think that it is my load thats messing it up, even if the powder was almost exact in each case???
     
  4. jeffro

    jeffro Well-Known Member

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    Some loads have more of a spread than others. You could try another load and see what you get with it. You can also try another primer and see if that helps.
     
  5. ReDnEcKBoHuNtEr

    ReDnEcKBoHuNtEr Member

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    ok, i havent even tested the drop chart with these loads yet. so im going to start with that and if it makes a big difference ill go back to the drawing board but i dont think that 27 fps should make a huge difference at only 500yds
     
  6. jeffro

    jeffro Well-Known Member

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    It will not be as much, as if you were shooting at 1000yrds.
     
  7. johnnyk

    johnnyk Well-Known Member

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    Do a drop chart using the 3599fps and do another using the 3626fps then compare the two at distances out to 500yds and you'll know. JohnnyK
     
  8. Hairtrigger

    Hairtrigger Well-Known Member

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    I have several of my favorite loads that have more than 27fps spread. No worries there
    How many loads were checked? High quality chronograph?
    Were all of the Rem cases from the same lot?
    Were all of the bullets weighed and the same weight exactly?
    was a fouling shot fired from a clean barrel?

    I am not trying to be an ass but there are many more variables also
    again 27 fps spread is not what I would worry about if the load groups well on paper
     
  9. J E Custom

    J E Custom Well-Known Member

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    27 ft/sec is not bad for light 22 cal bullets but you will want to get in the 10 to 15 area to
    shoot 500+yards.

    Standard deviations are a indication of load quality. (The lower the SDs The better the load).

    If you can get in the single digit SDs (.09 - )you are home.

    The larger/heaver bullets of the 7/08 should be easier to get lower numbers.

    Always use 5 or more shots to calculate SDs and ESs.

    J E CUSTOM
     
  10. ReDnEcKBoHuNtEr

    ReDnEcKBoHuNtEr Member

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    ok thanks johhny, thats a good idea...kinda common sense if i would a thought about it a little