The linearized angular motion of a symmetric missile is developed in some detail with some consideration of the rolling motion, drag, aerodynamic jump and the effect of varying coefficients. The tricyclic motion of a missile with misaligned control surfaces is briefly considered. This linear theory is, then applied to the analysis of ballistic range data. Next, simple cubic nonlinearities in static moment and Magnus moment are treated by a quasi-linear analysis and these cubic coefficients obtained from ballistic range flight data. More generalized relations for arbitrary symmetric nonlinear terms are derived and their use in the construction of 'amplitude' planes indicated. These amplitude planes have proven to be quite useful for the prediction of missile flight performance. Finally, the influence of strongly nonlinear static moments is determined by a perturbation method which makes use of two quasi-constants of the motion -- total energy and angular momentum.