Southpaw...Go back and look at your formula again and you will notice that it is the bullet diameter, not the weight of the bullet in pounds, that is squared. The formula of Sectional Density (a bullet's weight in pounds, divided by the square of its diameter, in inches) has been used for years to compared the potential penetration of bullets. It works fairly well on bullets of near weights, however the more weight you add to the formula the further away one gets.The more advanced formula: Bullet Weight in pounds (w/7000) divided by the Area of cross section of the bullet (pi X Diameter of the bullet squared/4) gives a better factor for comparison of potential penetration. This works only if the Form of the nose is is same on both bullets and does give more consideration to the Mass of the bullet.In many of the published penetration numbers we see nowdays the nose form factors is grossly overlooked on bullets of the same Sectional Density. All these numbers are nice to play with on a rainy day and may give some insight in comparing one bullet's potential against another, however they have little to do with actual killing power. Physics says that a bumblebee's body weight compared to the area of its wings times the strokes per second....the bee can't fly! Think about that the next time you ponder the physics formula in ballistics! That is exactly way we run actual tests in the field on living tissue.
Best Regards as Always, James
(Edited by James Gates at 7:21 am on Aug. 14, 2001)