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More on Sectional Density


What is "Sectional Density" and what is it used for?
  • Sectional Density is a value that relates the ratio of the density, or weight, to the cross-sectional area of a bullet.
  • Sectional Density  is the Weight of a bullet, in pounds, is divided by the diameter squared of the bullet.
  • Sectional Density is used in the calculation of a Ballistic Coefficient.

    A Ballistic Coefficient is the Sectional Density of the bullet divided by the Bullet Form Factor.

    Weight in grains = G

    Weight in pounds = P (There are 7,000 grains in one pound)

    Diameter in inches = D

    Sectional Density = SD

    P = G ÷ 7000

    SD = P ÷ D ÷ D

    A 250 gr. bullet with a diameter of 0.452 has a Sectional Density value of 0.1748

    SD = ( 250 ÷ 7000 ) ÷ .452 ÷ .452 = 0.1748