The problem, which has been known for years, is that the end of the #4 turnout's point is not, well, a point, but is cut off square. Also, there is no 'notch' for the points to sit into. So we do two things: 1) file a notch in adjoining stock rail for the points to sit into 2) sharpen the points. It goes very quickly and is very easy to do.

To carve the notch in stock rail, I put the points in the straight position, then use a small thin file and carve a notch in the adjacent stock rail. This provides a place for the points to 'sit' into, and thus provides a smooth path for the wheels/flanges.