Possible Duplicate: How to modify the bullet trajectory based on the ballistic c

Question

Possible Duplicate:
How to modify the bullet trajectory based on the ballistic coefficient?

I am new to the physics surrounding bullet trajectory and how it is calculated. I am a software developer and I am working on a ballistics calculator. I am using wiki for the trajectory calculation.

I am currently using the equation under the "Angle ? required to hit coordinate (x,y)" section. This is all well and good, but it doesn't take into account the drag of the bullet(ballistic coefficient).

I have searched all over trying to figure out how to apply the coefficient to this equation. I am really at a loss and and would be very thankful for any direction in this matter. Maybe I have a gap in my understanding, but I have found plenty of other calculators and other documentation on trajectory and the coefficient but nothing that marries to the two together.

Explanation / Answer

The problem you're having with not accounting for bullet BC is that it's a relative number. G1 and G7 BC are both based on a prototypical bullet design with a BC of 1.0.

The thing that further complicates your research is that BC is relative to velocity - it changes as the velocity changes. Some bullet manufacturers, such as Sierra, give relative BC's based on velocity bands: http://www.sierrabullets.com/bullets/BallisticCoefficient-rifle.pdf

In other words, ballistics coefficient is more a function of velocity, and therefore elevation, temperature, humidity, etc., than a hard number like c or pi.

Probably the best reference you'll find for this is Bryan Litz's "Applied Ballistics for Long Range Shooting" http://www.appliedballisticsllc.com/Book.htm
I was able to use the feedback from the physics forum Ultimately it was that response that gave me the most detail and enabled me to complete my own app.

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