Lance,
I have used two methods to mount the heads and will try to describe them for you.
The first method: Slot and round the tips of some shafts (I used Chundo shafts footed with purpleheart) to fit the thickness of the broadheads. Each head is friction fitted to a shaft, spun, adjusted as needed, then held in place temporarily with super glue. Next the shaft and arrowhead tang was wrapped with artificial sinew soaked in two ton epoxy. A final spin check is done and the arrow is set on its tip to dry. Next, another coat of epoxy is applied, curded, then filed smooth to adjust weight as needed and create a smoother transition between the arrowhead and the shaft.
The second method: This method is similar to the first except two small holes (3/32”) are drilled in the Damascus head about ¼” to 3/8” above the tang, on each side of the shaft after the friction fitting step. Instead of just wrapping the tang, also thread the artifical sinew through the holes using an X pattern then finish as described above.
I shot and killed two whitetail deer with the same arrow using the first method, both times the arrow passed completely through the deer. However, on the second deer, after passing through the deer the broadhead hit a stone. It came loose, and was slightly angled to the side (about five degrees). A few weeks later I was talking with a friend, Kent Brown, who also shoots Doug’s Damascus heads and he suggested drilling the holes to help reinforce the head. Like you, Kent had been worried about the short tang but hasn’t had any problems with the head coming loose or shifting with his method. The same head has worked without any problems on another four deer. I would prefer a longer tang on the broadheads but that would increase the weight beyond what most people want, or are willing to use. I talked to Doug about drilling the holes during the manufacturing process but we were unable to determine where the best location to drill them was. Also, the width of the shafts makes a big difference on how far apart the holes should be. Currently I am using the heads on cane shafts, whose diameters vary from arrow to arrow and the distance between the holes vary on most shafts.