> Angular momentum is a man made calculation So is linear momentum, really. I agree that you can analyze an actual physical gyroscope just in terms of linear

> Angular momentum is a man made calculation So is linear momentum, really. I agree that you can analyze an actual physical gyroscope just in terms of linear momentum without reference to angular momentum, though the calculations end up harder. But there are things that have angular momentum that doesn't obviously correspond to linear momentum (circularly polarized light and nonzero-spin elementary particles come to mind).