Was just pointed to this thread. My Ace did not have the 1/16" ball bearing. However, I did find a 4-40x1/8" set screw. 7/64" drill bit. Drilled a hole just deep enough to get the top of the set screw flush with the center of the cap. The steel set screw will self tap into the aluminum CDS cap.
Looks like the Leupold specific caps all have the zero stop bearing two hash marks to the right (CCW) of the CDS Zero hash mark. Using the 4-40 set screw and the 7/64" bit, I had to offset the hole three hash marks to the right (CCW) from zero to allow the CDS Zero hash mark to line up with the witness mark on the scope. Total of 40 cents and 30 minutes of tinkering.
