What does "ballistic coefficient" measure?

Ballistic coefficient is a key concept in internal and external ballistics that quantifies a projectile's ability to overcome air resistance during its flight. It is an important factor in determining how efficiently a projectile travels through the air. A higher ballistic coefficient indicates that a projectile is more aerodynamically efficient, meaning it can maintain its velocity better in the presence of air resistance. This efficiency can lead to flatter trajectories and less drop over a distance, which is essential for accurate shooting and understanding bullet performance. Factors that contribute to the ballistic coefficient include the projectile's weight, diameter, and shape, which all influence how effectively it navigates through the atmosphere.