Raymond, that is one fine looking jig and if I were still using jigs for pen blank drilling it would be one I would copy. I have for the past couple of years or so went to using just plain ole slip joint pliers. For antler especially it makes it easier for me to "line up the center" and drill it correctly for the first time. I do appreciate you sharing it with us though. Looks like a great project that will get a lot of use and be worthwhile.
God and family, the rest is icing on the cake.
I'm so far behind, I think I'm in first place.
Premier Bovine Scatologist
Host of the 2015 FAMILY WOODWORKING GATHERING