Drop chart HELP

Discussion in 'The Basics, Starting Out' started by tlk, Mar 24, 2011.

  1. tlk

    tlk Well-Known Member

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    Question: can I use only three or four distances to set up a drop chart with ballistics software to a high degree of correctness? Example: can I zero at 100, find my drop at say 300, 600 and 800 and then use a ballistics calculator to determine the drops (and ultimately a moa range card) for every 50 yds out to say 900 yds?

    Is there any reason to burn the powder and time to do this manually? Any help would be greatly appreciated.
     
  2. retiredcpo

    retiredcpo Well-Known Member

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    Well thats about the way we do it
    but we go back out and shoot the chart to verfiy the numbers
    ONce we get a load we chrono it shoot a few differant ranges and enter all that into the program get a chart out to 1000 yards then shoot the numbers to verify and adjust as needed
    The most we have everbeen off is a click or two
    retiredcpo
     

  3. texan79

    texan79 Well-Known Member

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    Yep, tried and true.
     
  4. royinidaho

    royinidaho Writers Guild

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    Yep! .
     
  5. tlk

    tlk Well-Known Member

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    So you guys are still shooting the entire range card for verification of data? I was under the impression (hoping really) that if I got three or four points in an arc each at a specific distances any point along the arc could be calculated with a standard fomula, and it would be all good with no need to verify. It's fine that it needs to be done, but what causes the delta between the math and the actual arc of the bullet?
     
  6. retiredcpo

    retiredcpo Well-Known Member

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    Well I supose you could assume it was all good but we wont take a shot at an game animal unless we know our drop for the the shot
    Now a coyotee or rock chuck we would take the shot.
    Besides I like to shoot so dont mind shooting the chart
    pratice makes you better
    If the chart is close you wont burn very much ammo
    one a round or two for each yardage
    Go shoot it and make sure.
    Sounds like you havbe never shot long range, Time behind the gun would help you out
    Just my 2 cents
    Retiredcpo
     
  7. J E Custom

    J E Custom Well-Known Member

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    You have to verify to be sure that the numbers are correct, After all it is only a formula and
    a computer.

    The cause for the delta is normally that the listed BCs are effected by velocity,twist rates, ETc
    and are normally not correct from the manufacture.

    You dont have to check every distance, but I would recommend at least two(Middle distance and
    the max distance to be shot.

    It does not matter what the BC and drop is, what matters most is the accuracy of the drop chart !

    J E CUSTOM
     
  8. tlk

    tlk Well-Known Member

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    Response erased. Apologies to retiredcpo. I was out of line.
     
    Last edited: Mar 25, 2011
  9. rscott5028

    rscott5028 Well-Known Member

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    tlk,

    I sure didn't take it that way. But, my blood sugar is just fine right now.

    Everyone has different standards as to what level of detail they feel comfortable with.

    Some are happy to chrony at 100 yds and go LR Hunting. Others aren't satisfied until they shoot every distance, altitude, etc.

    It's all about confidence.

    If you have a good known zero and your curve matches the software without a lot of manipulation, and your rifle groups well at long range, then you'll be more eager to take a shot.

    The more you have on the line, the more confident you'll want to be.

    You may be an expert. So, I don't want to come off sounding condescending. But, there is a big difference between paper/steel and hunting. Besides the obvious, ranging animals in the field and getting set up for the shot can be a big deal. As such, there's less room for error and the more dope you have on your rifle, the more confident you'll be when the time comes.

    If you knew all this, I apologize. Perhaps it will benefit one of the other newbies in the Basics, Starting Out Forum.

    Best,
    -- richard
     
  10. tlk

    tlk Well-Known Member

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    Richard, thanks for the help.

    The lesson that I am hearing is that if I want to set up a new load and utilize ballistics software then using the software and shooting at each distance (say every 100 yds) are parts of the process, not complete processes by themselves.

    Basically the software will get me close but still must be tweaked to match the actual field results is what I am taking away from this.
     
  11. rscott5028

    rscott5028 Well-Known Member

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    That's correct.

    Additionally, I find a chrony to be extremely helpful although not infallable. If you know the MV and BC and have a good zero, you're well on your way.

    But, you can back into it by shooting a few distances out to longer ranges and then infer the MV as you described.

    Happy hunting!
    Richard