Sectional Density

dennis53

How do you calculate sectional density? Are there units associated with S.D.? or is it just a number.?

Thanks,

Dennis53

mac59

Go to ChuckHawkes.com and he has the equation and tons of data for different caliber and bullet grain sectional densities.

JustC

http://www.eskimo.com/~jbm/topics/secdens.html

Ray B

SD is the bullets weight divided by the square of it's diameter. If the weight were divided by the bullets radius squared times pi(3.14...) you'd get the average weight per square inch, but as it is you get a number that is proportionate to the average weight per square inch. Some put a lot of stock in a high average weight per square inch for getting penetration in the target, but penetration is more a function of momentum of the bullet and ballistic shape as it pushes through the target.