I recently purchased some DeWalt "Pilot Point" drill bits thinking that
their pilot point, coupled with their seemingly "shallow bite" would
facilitate drilling through various hard points like the wing spar
transition and fitting holes.  Not!  The bit penetration was almost violent,
resulting a  hole that was barely salvageable.  Albeit, my technique may be
some what lacking and I'm sure the bits will do fine on other materials.
Subsequently, I ventured out to find some "Unibits" as suggested by someone
here on the LML.  At my local Lowe's, I located a "3-pack" of Unibits with
various hole sizes and tapers including the 7/16" size I was seeking.  Only
$59, how sweet!  The bit penetrated the spar hard point like a hot knife
through butter, generating only a fine powder with no "shards" and a
perfectly round hole!  Thank goodness for LML (I should have listened the
first time ...).

Dana Westphal
L2K-165
(Building over "geologic time")