Constant ASM_TO_ICAO_BC 

pub const ASM_TO_ICAO_BC: f64 = _; // 0.98237309412349294f64

Multiplier that converts an Army-Standard-Metro-referenced BC to the ICAO-referenced value this engine’s retardation formula expects (MBA-1365):

BC_icao = ASM_TO_ICAO_BC * BC_asm

A denser reference atmosphere implies a numerically SMALLER published BC for the same physical bullet (the same real drag is attributed to a “worse” — smaller — BC when the assumed air is denser), so this ratio is ASM_DENSITY_LB_FT3 / ICAO_DENSITY_LB_FT3 (< 1), not its reciprocal. Evaluates to 0.98237 to 5 decimal places (asserted by a unit test in cli_api.rs).