External Ballistics of Rifle Bullets

The science of projectiles and firearms is known as ballistics.  This field is so broad that there are four sub-fields: internal, transitional, external, and terminal ballistics.  This website aims to describe the various factors effecting the trajectory of  rifle bullets with respect to external ballistics only, as this focus alone is enough to develop an appreciation for the complexity in forming a firing solution.

External ballistics focuses on the bullet's performance while in flight and is no longer being propelled.  In other words, all the factors that come from gun and cartridge selection as well as the factors that determine effectiveness against the target are not to be considered.  This might seem to overly simplify things such that one can simply expect the bullet to hit where the gun is pointed.  Practically, this is true at short ranges due to the very high speed that bullets travel.  At longer ranges, such as 1000 meters, calculations are usually required to compensate for variations in the flight path.

Beyond what is described in the links below is an abundance of complexity that this website will not discuss, such as spin stabilization, the Coriolis effect, the transonic zone, and the Magnus effect to name just a few areas.  In practice, field calculations need to be efficient and the process has been greatly simplified for application by the shooter.  Further reading on the web is encouraged.

Note: Depending on the browser, equations may not display nicely.