External ballistics or exterior ballistics is the part of ballistics that deals with the behavior of a non-powered projectile in flight.External ballistics is frequently associated with firearms, and deals with the unpowered free-flight phase of the bullet after it exits the barrel and before it hits the target, so it lies between transitional ballistics and terminal ballistics.However, external ballistics is also concerned with the free-flight of rockets and other projectiles, such as shells, rocket-assisted projectiles, balls, arrows etc.