Sectional density is a crucial ballistic concept determined by dividing a projectile’s mass by the cross-sectional area it presents as it travels. For example, a long, thin projectile with a small frontal area will have a higher value than a short, wide projectile of the same weight. This value is typically expressed in grams per square centimeter or pounds per square inch. Understanding this metric provides insights into a projectile’s performance, particularly its ability to overcome air resistance.
This metric serves as a valuable predictor of projectile penetration and external ballistics. Historically, it has played a significant role in the development and refinement of projectiles for hunting and military applications, enabling designers to optimize for longer range and greater effectiveness. A higher value generally correlates with better long-range performance and deeper penetration in target materials. This is because a projectile with a higher value retains more energy and velocity downrange, leading to enhanced effectiveness.