To round out their many ammunition and reloading products, Hornady has released a ballistic calculator app for smart phones. Inside the app is Hornady’s 4 Degrees of Freedom (4DOF) ballistic calculator, which is based on projectile drag coefficient (not ballistic coefficient), plus the exact physical modelling of the projectile and its mass and aerodynamic properties.
“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 Chief Ballistician. “This program (4DOF) incorporates the projectile’s movement in the standard three degrees but also adds its movement about its centre of gravity and subsequent angle relative to its line of flight, which is the fourth degree of freedom.”
There are quite a few (about 75) different bullets available within the app but even if you can’t find your bullet, the basic calculator can still be used without the fourth degree of freedom. Another feature shooters will find handy is the ability to save previous calculations, which can quickly be brought up as required. The inclusion of Bluetooth also allows the app to automatically gather information. While similar apps or calculators on websites might exist, the fact this is an app downloaded onto your phone means it can be used even when there is no Internet available.
While Hornady deserves praise for making the app free, lots of users have been disappointed that the app requires a login to use. Some people won’t mind but if you are careful with your information being used on online, this could be a deal breaker.