Re: Drag Model Help
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jig Stick</div><div class="ubbcode-body">im using the JBM Ballistic program on my Ipad / Iphone. What variables are different between the two drag models? I ordered Applied Ballistics for Long Range Shooting, and im sure the info that im looking for is in there, but it hasnt been delivered yet. And im going coyote hunting today. I like using my phone to cross reference my DOPE sheet.</div></div>
Jeepers Jig Stick, I don't know what kind of math goes into figuring the G7 but it probably is a few pages long. Using the G7 will just get you closer to what you will encounter in real life for a high speed bullet. G1 is based on a flat based spitzer and the comparison between it and boat tail bullets will give you a much higher BC.
The G7 is closer to the newer bullet shapes and this will give you a lower BC. The G1 is preferred by a lot of bullet manufacturers because of the higher numbers and that SELLS bullets. But for the long range shooter, G7 will be closer in calculated trajectory to your actual bullet drop so it is the one you would want for long rang shooting when calculating at longer distances.
I copy and pasted this little chart from Wikipedia.
http://en.wikipedia.org/wiki/Ballistic_coefficient G1 or Ingalls (by far the most popular)
G2 (Aberdeen J projectile)
G5 (short 7.5° boat-tail, 6.19 calibers long tangent ogive)
G6 (flatbase, 6 calibers long secant ogive)
G7 (long 7.5° boat-tail, 10 calibers tangent ogive, preferred by some manufacturers for very-low-drag bullets[10])
G8 (flatbase, 10 calibers long secant ogive)
GL (blunt lead nose)