Is the Shooter Ready?

Resources used in the Basic and Advanced Training versions

Sierra Infinity Software used to calculate data in the Basic Training version. Uses the G1 model. From Sierra Bullets

Hornady 4DOF® Ballistic Calculator a free online calculator also available for mobile devices. Data was obtained from doppler radar. Has a large library of Hornady bullets and bullets from other manufacturers as data is obtained. Used to calculate the trajectory data in the Advanced Training Version.

It is difficult to find exterior ballistic software that calculates Coriolis, Spin drift and aerodynamic jump accurately. The Hornady 4DOF® makes these calculations easy.

However - The online version of the software has two bugs. The Coriolis drift is combined with the spin drift if earth-based effects are turned on. To get the Coriolis drift, turn off earth-based effects, get the spin drift, then with earth-based effects turned on, add or subtract the actual spin drift from the value in the spin drift column.

The second bug gives a larger value for aerodynamic jump with 135 and 315 degree winds and an even larger value with a head or tail wind (when aerodynamic jump for head or tail wind should be zero) than for a full crosswind. You have to adjust the elevation value for these winds or you will get an incorrect drop. If aerodynamic jump is negative subtract from elevation (since it was added in) and if the aerodynamic jump is positive add to elevation (since it was subtracted). The mobile version has not been tested. The bugs have been reported to Hornady.

JBM Ballistic Calculators
Popular, free online calculators. Uses both the G1 and G7 models, has calculators for drag and stability and more. The Modified Point Mass Trajectory calculator has the ability to calculate spin drift, aerodynamic jump and Coriolis, but a great deal of data input is required that may not be readily availble.

Shooters Calculator is a free online calculator with the ability to use six different G models. Does not calculate earth-based effects, spin drift or aerodynamic jump.

Berger Bullets online ballistic calculator for Berger bullets. Also provides a calculator for bullet stability factor and barrel twist rate.

There are numerous choices for ballistic calculators for mobile devices. Search in google play and the App Store.

Books by Bryan Litz
Applied Ballistics, LLC
The go-to sources for advanced ballistics for the serious long-range shooter.

Rifle Accuracy Facts
Harold R. Vaughn
Republished by Precision Shooting, 1998
A classic for the long-range shooter
Read online or download for free in multiple formats

History of Ernst Mach at Aerospaceweb.org