The 647 grain round drops 32.2 feet after the second just like the 800 grain one, AS you stated...

Hi Ten60,

You have been led into some false assumptions there, the different weights do have an impact on the drop. Many people believe that things fall due to gravity at the constant rate of 32.2 ft/s/s because they assume that the acceleration will be constant because the force of gravity is constant but that is not true.

Let me explain with some simple math.

Let g = force of gravity

let m = mass of projectile

let a = acceleration of projectile

Now apply Newton's law F = ma

The force on any objectdue to gravity F = mg

So we get mg = ma

where m cancels out and of course a=g

Thus the notion that that the acceleration is constant at g = 32.2ft/s/s

What is wrong with this is that it ignores other important forces. It isn't only gravity at work on a projectile, drag forces play an important part.

For example if we represent the force due to drag with the character d our equation for the force F becomes F = mg - d

Now when we put that into Newton's law we get ma = mg - d

Now if we divide both sides by m to find the acceleration a we get a = g - d/m

Now you see that the acceleration isn't just g, it is less than g by the amount d/m. So the mass, and thus the weight does play an important part in ballistics if drag is included in your thinking.

Hope that helps...

Badboy