Cheaper than Dirt explains Ballistic Coefficients.
For many shooters, figuring out the ballistics of their rounds is akin to some arcane form of black magic. There are so many variables involved, and some of these variables have a much greater effect than others. Everyone is basically familiar with the effects of bullet weight and muzzle velocity, and a basic computation of your external ballistics and bullet trajectory can be computed using simple physics formulas that disregard atmospheric conditions and aerodynamic drag using only these components. But there is one aspect of aerodynamic drag that does have a significant measurable effect on bullet trajectory, and that is the ballistic coefficiency of the bullet. But what is a ballistic coefficient?
Pretty good read.
Now, I find it funny that many ardent gun-banners love to latch onto the myth that a gun's sole purpose is to kill. Ignoring the fact that intent is non-transferable, the design of a firearm is to generally propel a projectile, generally using expanding gasses. When it comes to what really has the potential to kill, you need to look at said projectile.
This is why it's generally easy to dismiss anti-gunner's positions. They're not based on facts, reality, or anything resembling logic. Unfortunately, we still have to combat them as ignorance is their strongest (and pretty much only) weapon.
Oh look, I made a pun!