Quote:
Originally Posted by zombietactics:
It's not a question of "dismissing" it, rather a point that it's not the important factor in play. You can derive crosssectional area starting with the radius as well ... it's just an innumerate way to look at the problem.

That is nonsense. Diameter is an important factor in the determination of crosssectional area. In fact, it is
the main determinant since п is nothing more than a constant.
Radius is simply one half of the diameter.
The formula for crosssectional area is
пr²
or, if you wanna express it terms of diameter
п(½D)²
because r = ½D
Any fourth grader can tell you this.
Either way you must use some function of the diameter of the bullet's expansion face to determine the crosssectional area of the circular face. For this reason, it is
the most important factor in play. You CANNOT determine the crosssectional area of a bullet without it.
ETA
If you don't believe me, perhaps you'll take it from here
http://en.wikipedia.org/wiki/Circle
Check out the illustration at the upper right corner of the page in the link.
Can't believe we have to argue such simple matters these days.