Which of the following describes a high ballistic coefficient projectile?

A high ballistic coefficient projectile is characterized by its streamlined shape, which allows it to maintain higher speeds and be less affected by air resistance during flight. This is crucial because a streamlined design reduces drag, enabling the projectile to travel more efficiently through the air.

When a projectile possesses a high ballistic coefficient, it means that it retains its velocity better over long distances and exhibits more stability in flight. As a result, such projectiles are commonly used in long-range shooting and various applications where accuracy and penetration are essential.

The other options do not accurately reflect the attributes of high ballistic coefficient projectiles. High air resistance and low mass would result in less effective projectile performance, while maximum expansion upon impact pertains more to hunting projectiles rather than the aerodynamic efficiency highlighted by a high ballistic coefficient. Finally, while a lightweight and fast projectile might seem advantageous, it does not necessarily imply better performance if it has a higher air resistance. Thus, the streamlined shape combined with reduced air resistance distinctly defines a high ballistic coefficient projectile.