A simple open source ballistics calculator

Build Status Ready Status


In the simplist terms, balística is an open source external ballistics calculator. More specifically, balística is a exterior balisitics calculator with some extra features tacked on. The program is named for the Catalan word for "ballistics".

Currently the project is in it's early stages and is still missing quite a few features I have planned for it. Feel free to jump in and help!

Current Features

Calculate drag using the standard drag functions G1-G8

The standard drag functions are an essential part of any ballistics program. It is simply a have-to-have.

Calculate using the Ingalls and British drag functions

These drag functions are older and a bit antiquated. They still work to an extent but you'd probably be better off with the standard drag functions. Regardless, balística can still compute them for you if you want.

Miller Twist Rule

The Miller Twist Rule is a mathematical formula dervised to help people calculate which bullets will work better in thier rifle based upon various factors. Including bullet length and barrel twist rate.

Greenhill Formula

The Greenhill Formula, in the same vien as the Miller Twist Rule is a much older formula for the same purpose that has been used for centuries now. It is the defacto standard for this type of computation.

Miller Stability

The Miller Stability calculation is a mathematical formula that calculates the estimated stability of a projectie using the Miller Twist Rule as it's base.


LibBalistica is a ballistics library developed incordination with balística that allows developers to build their own ballistics software application should they choose. LibBalistica is also unit tested to ensure reliable consistent calculations every release. With code developed independently of balística improvements can also potentionally be made without breaking LibBalistica.

Image Gallery

drag calculation
Calculating the drag of a .30-06 bullet.
miller twist
Calculating the twist of a .308 using the Miller Twist Rule
miller stability
Calculating the stabilit of a .308 using the Miller Stability formula.

Features In Process

PBR (Point Blank Range)

The PBR function clculates how far a given projectile can travel before the elevation needs adjusted to continue to hit the intended target. So, for example, a .30-06 may be able to hit the bullseye of a target at 0 yards all the way out to 200 yards before the elevation of the barrel of the rifle needs to raised in order to arc the trajectory in order to continue to hit the bullseye.

A database to store custom handloads in

I want to be able to create and store custom hand loads. I already have a SQL database strucutre worked out for this. I also have some basic data to load in it. But that's all I have. I don't even have Vala to talk to the database with.


There are several different graphing packages out there. I'd love to be able to graph the bullet through its trajectory. This is really a must have. Everyone expects this to be there.

Planned Features

Expansive Help Pages

I don't want to rewrite Wikipedia, but I'd really like to have a nice in depth look at whats going on in the software and how to properly use and understand the software in the help pages. The help pages do exist in a fleshed out form but need a lot of work expanding them out to be useful.

Other minor features

There are a lot of calculations out there! While I don't expect balística to be able to calculate all of them I see no reason to not try and do as many as possilbe. I'm sure there are a lot of still very realvent ones out there I haven't even started yet.

Helping out

Check out the code

~$ git clone git://

Build it

~$ cd balistica
~/balistica$ mkdir build && cd build
~/balistica/build$ ./../configure
~/balistica/build$ make && make test
~/balistica/build$ sudo make install

I'd prefer pull requets though Github to keep it simple, but patches through email are always welcome anyway.

Minimum Build Requirements:

Authors and Contributors

At this point I am the author and only contributor.

I have converted the GNU Exterior Ballistics Computer by Derek Yates to Vala. The GEBC is open source and licensed under the GNU GPL version 2. If you are Mr. Yates, or know him, I'd like to talk. I have some questions about the code.


Steven Oliver (@steveno)