August 19, 2016
Hornady Ammunition introduced a new kind of ballistic calculator based on patent-pending technology. The company is calling this new calculator the 4DOF (Four Degrees of Freedom) Ballistic Calculator.
The Hornady 4DOF calculator provides trajectory solutions based on projectile drag coefficient (not ballistic coefficient) along with the exact physical modeling of the projectile and its mass and aerodynamic properties.
Additionally, it is the first publicly available program that will correctly calculate the vertical shift a bullet experiences as it encounters a crosswind; referred to as aerodynamic jump.
With the use of drag coefficients, correct projectile dynamics, aerodynamic jump and spin drift, Hornady claims that the 4DOF ballistic calculator is the most accurate commercially available trajectory program available, even at extreme ranges.
"Current ballistic calculators provide three degrees of freedom in their approach; windage, elevation and range, but treat the projectile as an inanimate lump flying through the air," said Dave Emary, Hornady's chief ballistician. "This program incorporates the projectile's movement in the standard three degrees but also adds its movement about its center of gravity and subsequent angle relative to its line of flight, which is the fourth degree of freedom."
Using Doppler radar, Hornady engineers calculated exact drag versus velocity curves for each bullet in the 4DOF calculator library. Combined with the physical attributes of the projectiles, the 4DOF calculator is simply more accurate for long range hits than using BC based systems or custom drag curves based off of limited data collection points.
"This calculator doesn't utilize BCs (ballistic coefficients) like other calculators," Hornady Ballistics Engineer Jayden Quinlan said. "Why compare the flight of your bullet to a standard G1 or G7 projectile when you can use your own projectile as the standard?"
The Hornady 4DOF Ballistic Calculator is available for free at: www.hornady.com/4dof.