The byrd crossbill is interesting for being both a hawkbill-style blade and a chisel grind stock.

I know the fact that it is chisel ground means that only one side is sharpened, and the burr cut off of the other.

Does anyone know what that sharpened side's angle is? I'm attempting to sharpen it on the sharpmaker (with aftermarket congress tools stones, 320 grit) and it's definitely not 20 (40 on the sharpmaker) or 15 (30) and I'm afraid I'm going to end up damaging the knife trying to sharpen it to one of these angles.