MCTRAJ · INTLIFT · MCDRAG · McGyro

McGyro

Estimate of gyroscopic stability factor (SG) for a uniform-density projectile (R. L. McCoy, April 1986). Uses MCDRAG geometry plus density and twist. Output: launch Mach, launch SG, and twist rate N for SG = 1.5.

McGyro inputs

Do not enter center of gravity — the program assumes CG at the volume centroid.

Projectile identification Reference diameter (mm) Total length (calibers) Nose length (calibers) Headshape RT/R Boattail length (calibers) Used in input echo; stability formulas use DB via (1−DB²) Base diameter (calibers) Meplat diameter (calibers) Projectile density (g/cc) Rifling twist rate (calibers/turn)

N (SG=1.5) is the slowest acceptable twist rate from the original McGyro criterion.