JD, how is this for an idea. pre drill the holes such that when you go with the final sqr-end bit, that it's diameter is such that each hole just barely cuts into one another.
the only reason this is not possible with a drill-press and normal drill-bits, is the fact that the bits are so bendy and braky..
this will give the formed pins the perfect shape. the Sqr-end bit will also not be so prone to wander, as it will be cutting on the perpendicular plane to the downward force applied.