fyrfyter.
true, but along with that view comes the fact that the lowerer the angle, the thinner the metal at the edges and the easier it is to bend , chip or deform. This changes depending upon the shape of the head, the thickness of the head and the hardness and type of the metal in the head.
Without performing all of the metalurgic tests and in vivo shooting / pennetration testing, I am guessing that you should experiment, starting with a thicker angle and stop when you can achieve a very sharp blade. I don't believe there will be a substantial difference in bevel surface area between 25 degrees and 20 degrees when you take into account the latter portion of the broadhead is one metal layer thick in the heads he is asking about.
Another study might be fun.... IF the front third of the blade is triple thick, as is the case here.. does it even matter if the rest is single beveled ? Will IT drive the twist in the blade's travel.
ChuckC