Posted: 5/19/2005 10:33:17 AM EDT
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I am working on programming my scientific calculator to provide range, wind, and angle dope for 168 FGMM and one specific rifle. I want to simply insert the target size, target mils, cosine angle, and have the calculator spit back the range, MOA come-up, and mil-holdover. Once this is completed, I want to be able to mil-range at any power with my Mk4 and have the program compensate for the change in mil-dot spacing. That’s the goal, here is a question: I am taking known ballistic data at different ranges and modeling it from 100-1000 yards. The trajectory (in MOA) will be in equation form instead of a “look up” table. I wrote a 2nd order polynomial equation for the bullet drop (MOA). I noticed that the last term in the polynomial tends to be real close to the bullet’s ballistic coefficient. Is it? |
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Looks to me like the last term is just the bullet "drop" at zero distance (in other words it's related only to the geometrical relationship of the scope and bore). ETA: By the way, the 2nd order and 4th order equations look so different that it's difficult to believe they are both approximations of the same bullet flight. Have you run a couple of numbers to confirm the coefficients are correct? |
Do you realize that at, say, 1000 yards, if the constant was increased by .5 to .9845 (a ridiculously high BC...) that drop would only change by 5.25 inches? Ergo, it's only coincidence, as changing BC that much would result in a HUGE change in drop at that range. |
Per the given data, the MOA zero is at 100 yards, which provides a .5 MOA error from the 2nd order equation. All else zero, the 4th order equation shows a different offset. I never defined a intercept point like in a linear Mx+b equation of a line. |
Good point, I should have compared the variable against the JBC calculator. |
