Drag Functions

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by blygy, Dec 29, 2006.

  1. blygy

    blygy Well-Known Member

    Aug 21, 2006
    Can anyone explain the drag functions on ballistic calculators??

    I ussually use the G1 function but I'm not sure if this is correct.


  2. Michael Eichele

    Michael Eichele Well-Known Member

    Jan 6, 2003
    To get an accurate trajectory drop chart, it takes two numbers. BC and drag function. G1 is the most common. If you dont have real world drop data to compare your calculator results to, use G1. If you have real world results say at 300, 600, 800 and 1000 yards and even more imbetween, then if G1 and any BC combo doesnt match, then you try G5 and a lower or higher BC. If that still doesnt match, yoy try G7 and a lower or higher than G1 BC. Sooner or later, it will match. Many combo's will get you an accurate 1000 yard drop, but your calculator may have the mid range points higher or lower than your real world drops if youre not using the right drag function. They are also very unpredictable. YOU MUST test your rifle load combo to get your calculator to give you accurate results. So you ask, what is the point of a calculator? The point of them is so that after you have established a real world BC and drag function, it will show you predictable changes when the air density changes.

    Clear as mud??