BC is the ratio of how far a given bullet travels in one second to how far the standard bullet travels in one second.
This is absolutely incorrect.
BC is defined as the Sectional Density (SD) of a bullet, divided by it's form factor referenced to a standard projectile. BC has units of lb/in^2.
In equation form:
Here is the rest of the Wiki article:
Ballistic coefficient - Wikipedia, the free encyclopedia
Modern Exterior Ballistics by Robert McCoy, page 101
Exterior Ballistics by George Klimi, page 46
Rifle Accuracy Facts by Harold Vaughn, page 203
I don't wish to engage Mr Perry, just wanting to share my information with others who are interested.
Interesting that he's using a 'hybrid' atmosphere. Given that fact, I have no idea how to properly adjust BC's for exbal.