If you closely examine the spud from the side––good light and a magnifying lens will help–– you will notice a change in diameter of the spud shaft from thin to thicker (small diameter to larger diameter).

Examine the place where this transition takes place, and you will see a slight radius is present, instead of a sharp, discrete change in diameters.  This radius is what eliminates the crimp, and  is what impresses a rounded (radiused) edge into the rim of the primer pocket.  The crimp is eliminated, and the radiused edge of the pocket helps the installation of the new primer, by acting as a sort of funnel.   A good rule of thumb is to seat the spud so that the larger diameter portion of the spud just stops at the beginning of the primer pocket.  IOW, seat the smaller diameter of the spud, and the radiused portion, and stop there.  

So, to do its' job, the spud must be seated so that the radiused portion seats fully into the primer pocket, but no more.   If you press the spud in too far, you will bent the rather thin  adjustable spindle upon which the inside of the bottom of the case rests.

To do this operation properly, you WILL have to sort cases by headstamp, as the internal dimensions vary quite a bit.  That is why you will adjust the spindle for each headstamp.  You begin by the spindle adjustment being too short, and the spud just entering the primer pocket.  Lengthen the spindle gradually, until the radiused portion of the spud is fully seated, and stop there.

If you look at the edge of the primer pocket as you make the spindle adjustments, you will see the radius on the spud begin to impress itself into the brass.  Once you see the beginnings of a radius on the edge of the primer pocket, you do not have much adjustment left to make, so go slowly.  If you go a little too long on the spindle, you will notice a significant increase in effort in manipulating the press.  Back off a tinch, and you will feel the effort go back to its' former, lesser level.

It is inevitable that you will bend a spindle, so it is strongly advised that you obtain some spares––they come in 2 sizes, IIRC–– at your earliest conveniance.  Sometimes the spindle can be straightened, sometimes not.  Spares are good.

The techs at RCBS are quite good, and you can call their toll-free # if the above has not helped.