Main Pages


Here's how you can tell if ballistics software is technically correct.

Most software publishers allow you to download a demo of their software so that you can try before you buy. Once a demo is installed, it takes only a few minutes to test the technical correctness of the software.

1. Check if the software calculates the effects of head and tail winds on downrange velocity. This is easy to test, just enter some convenient values for muzzle velocity, ballistic coefficient, and bullet weight. Next enter a wind speed of around 20 MPH and set the direction to be a head wind (12 O'clock or 0 degrees), and record the calculated velocity for 500 yards. Now change the wind direction to be a tail wind (6 O'clock or 90 degrees) and compare the head and tail wind velocities at 500 yards. The velocity of the bullet with the tail wind should be higher than the velocity of the bullet with the head wind by anywhere from 1 to 10 percent depending on the particular values you entered. What you will find, however, is that most software reports the same velocity regardless of the direction of the wind and that's wrong.

2. Compare the program's calculated velocities to that of a trusted source. Many of the reloading manuals include ballistics tables, but some of them don't agree with each other and are probably wrong. Without a doubt, the most scholarly treatment of exterior ballistics is found in the Sierra Bullets reloading manuals, but starting with edition 5, Sierra no longer publishes ballistics tables. The tables in Nosler's fifth edition and Hornady's sixth edition volume 2 agree with the tables published in Sierra's edition 4, so they are the gold standard. If you have either the Nosler or Hornady manuals you can check the accuracy of a program's calculated downrange velocity values with the tables in these manuals. The tables are for standard sea level conditions, so be sure the program is using standard conditions as well. Also, make sure you are comparing values at the same range. Some of these manuals have tables with range in meters rather than yards.

We have checked Ballistic Explorer extensively against the Hornady tables and found nearly an exact match. With other software, however, you will find that the calculated velocities are off by 10 to 50 f/s second at 500 yards. The real advantage of software is that it's not limited to standard conditions, but if it's not correct a sea level conditions, it's not going to be correct for other conditions.

Internal Ballistics

Ballistic Explorer doesn't address internal ballistics and here is why. Many factors that can be ignored in 20 mm and larger calibers become highly significant in sporting calibers. It's impossible to accurately predict pressures in sporting calibers without considering these factors. The best that can be achieved with current models is a usually safe (reasonable) powder charge. Of course, the publishers of internal ballistics programs will disagree, but you can check for yourself.

A number of newer reloading manuals were developed using modern pressure measuring equipment. Examples include the current reloading manuals by Hornady, Nosler, Sierra, and Swift. Run the internal ballistics software on some convenient load and then compare it to a load of the same caliber, bullet, and powder type in a trusted reloading manual. What you will often find is that the optimal load reported by the internal ballistics program is below the starting load in the manuals. It's good these programs error on the side of safety, but just imagine the anxiety you'll go through working up to factory ammo velocities when the software is predicting dangerously high pressures. Of course you can't depend on the software always being wrong in the same direction, so you'll still need your reloading manuals.

Ballistic Explorer is a trademark of Dexadine, Inc.   All other products mentioned are registered trademarks or trademarks of their respective companies.
Last updated: 2014
Copyright 2014 by Dexadine, Inc.