Garzke and Dulin Penetration Formula

(Created April 2024)

This equation comes from a paper on NAVWEAPS titled “The Garzke and Dulin Empirical Formula for Armor Penetration” (External Link) (Internal Link) by John Priestle which reverse engineered the formula Garzke and Dulin used in their books to show armor penetration at zero striking obliquity.

T = (0.000469) * W0.5506 * D-0.6521 * V1.1001

Where:

T = Armor Thickness (inches)
D = Shell Diameter (inches)
W = Shell Mass (pounds)
V = Striking Velocity (ft/sec)

EXAMPLE: What is the Penetration in inches of a 20 inch (508mm) shell weighing 5,289 lbs and having a muzzle velocity of 2500 fps?

[NOTE: This is a scaled up USN 16”/50 Mk 7 Superheavy shell design]

(0.000469) * 52890.5506 * 20-0.6521 * 25001.1001 = 40.825 inches penetration

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Projectile Diameter (inches)
Projectile Mass (pounds)
Striking Velocity (ft/sec)

Armor Penetration (inches)