ballistic coefficient: a standalone construct

The ballistic coefficient measures how well a projectile overcomes air resistance in flight, expressed as its sectional density divided by a form factor, or equivalently as the ratio of the projectile's retardation to that of a standard reference projectile. A higher ballistic coefficient means the projectile sheds velocity more slowly, so it drops and drifts less and retains energy farther downrange. McCoy's Modern exterior ballistics sets out how the coefficient is defined against standard drag models and used to predict trajectories. The referent is a single number summarising a projectile's aerodynamic efficiency relative to a reference shape.[1]

Unit

A dimensionless ratio (commonly reported in lb/in² against a standard drag model such as G1 or G7)

Recovery means

Not applicable

Measured by

Derived from sectional density and form factor, or determined empirically from measured velocity decay over range