This is good stuff, especially the web site you included. I'm still digesting the info they have. I think the problem arises in the fact that, using your example, a 3000 fps projectile is encountering a 2045 mph head wind. I would think this GREATLY reduces the Magnus Moment. If my thinking is correct, the 2045 mph head wind combined with a 15 mph cross wind would create an effective yaw against the wind of only about 1.3 degrees versus 90 degrees (perpendicular air flow). And as the site says, "The Magnus force vanishes in the absence of rotation and in the absence of a yaw angle." I believe your calcutlations only account for perpendicular air flow. To quote the site further, "The Magnus force is usually very small and mainly depends on bullet geometry, spin rate, velocity and the angle of yaw." This leads me to believe that the head wind (especially in super-sonic flight) nearly negates the Magnus Moment.

The curve ball and the golf ball are spinning on an axis nearly perpendicular to their direction and hence a head wind aproximately equal to their velocity. That's why they encounter a noticable effect. The bullet on the other hand is spinning on an axis parallel to the head wind.

This does raise an interesting question though. In the case of an overstabilized bullet that maintains it's orientation in relation to the plane of the barrel, as the bullet starts to decend toward it's target the effective yaw in relation to the "head wind" would become greater and greater and the Magnus Moment might besome great enough to move the bullet left or right depending on the direction of the rifling.

By the way what number did you use for p? I might have missed it, it's late and I'm tired.