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This report describes a computational study to understand the free roll, pitch, and yaw motion of a canard-controlled, fin-stabilized projectile. Numerical computations were performed for this projectile using an advanced coupled computational fluid dynamics and rigid body dynamics technique. Additionally, the coupled approach was tailored to be constraints-based for the rigid body dynamics allowing for pure pitching and pure rolling motions to be studied prior to considering the full roll-pitch-yaw motion. Flow visualizations and aerodynamic force and moment computations indicate unsteady canard stall at high angle of attack and significant interaction of these canard vortices on the afterbody-fins. Parameter estimation was performed to obtain aerodynamic coefficients, assess the aerodynamic model, and understand the roll-pitch-yaw coupling. These results suggest that improvements to aerodynamic modeling are necessary to better capture high angle-of-attack phenomenon such as unsteady canard stall and vortex interactions. Analysis of the pure pitch and pure roll predicts the coupled roll-pitch-yaw motion well with the exception of unsteady and interaction effects during periods of high angle of attack.