Which factor can affect external ballistics?

Gravity plays a crucial role in external ballistics, which is the study of the behavior of a projectile in flight after it has left the barrel of a firearm. Once a projectile leaves the muzzle, gravity begins to exert a force on it, pulling it downward toward the earth. This acceleration due to gravity affects the projectile's trajectory, causing it to follow a curved path instead of a straight line. Understanding how gravity influences bullet drop is essential for accurate shooting, as shooters must compensate for this effect at various distances.

While barrel length and projectile shape are important factors that can influence a bullet's velocity and stability, they do not fundamentally change the impact of gravity on the projectile's trajectory during its flight. Ammunition color, on the other hand, has no effect on ballistics and does not influence the bullet's performance in terms of external ballistics. Therefore, gravity is the primary factor affecting external ballistics in this context.