What is the primary factor in determining the effectiveness of a projectile in terminal ballistics?

The effectiveness of a projectile in terminal ballistics primarily hinges on its ability to transfer energy effectively upon impact with the target. This energy transfer is critical because it determines how much damage the projectile can inflict on the target. A projectile that can rapidly convert its kinetic energy into other forms, like heat and deformation, will create a more significant wound channel and potentially incapacitate the target more efficiently.

While the speed upon contact with the target is an important factor influencing the kinetic energy of the projectile, the real measure of effectiveness lies in how that energy is utilized upon impact. Similarly, the shape and design of the projectile do play essential roles in determining factors like aerodynamics and penetration, but these aspects ultimately serve the broader purpose of energy transfer. The color of the projectile is irrelevant to its function in terminal ballistics, as it does not affect the physical properties required for effective energy transfer.