A needle 0.4 x 0.7 mil is a conical tip. But it has a back and front small cut to make it a little like an elliptical. It´s not a real elliptical.
A true elliptical tip should have a bi-radial profile, a shaved ball point is really neither, but they are and have been sold as elliptical tipped. It's possible they show less "pinch effect" inner groove distortion but lack the finer tracing ability of a bi-radial elliptical tip.
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