Author Topic: B.C.? (Read 671 times)

S.B. · « **on:** April 09, 2003, 01:20:35 PM »

Anyone have a formula for figuring balistic coeficientcy?

Paul H · « **Reply #1 on:** April 09, 2003, 03:13:50 PM »

I don't think there are any accurate formulas, unless you happened to be a wiz at computation fluid dyanmics :eek:

The best route is to use a chronograph at the muzzle, and at 100 yds, and calculate based on velocity loss. If you get an Oehler PBL, and use the 35 at the muzzle, and another one, or the audio target at 100 yds, it'll figure it out for you.

KN · « **Reply #2 on:** April 09, 2003, 06:44:35 PM »

I believe my Sierra ballistics program has that for about every bullet made. KN

SingleFan · « **Reply #3 on:** April 10, 2003, 05:37:57 AM »

Computation Fluid Dynamics? I had several fluid dynamics courses in enginering school and don't ever remember that term?

Sure air is treated like a fluid but that factor is assumed as a constant whenever I've seen BC discussed. Bernoulli's equation hasn't ever come into play; at least in discussions I've seen and that's the backbone of fluid dynamics.

It's always been more a matter of section modulus and other physical characteristics of the bullet.

Don't bother tyring to have a canned formula. Every manufacturer I've seen provides the data; even some of the smaller custom cast firms.