It is possible that the broadhead cuts a bigger hole in the hide than the actual cutting diameter. When that happens its because the broadhead is actualy stretching the hide before it cuts it, but the hold throught the vitals is still gonna be the same as the blades. And to be honest if your completely blowing through the deer and sticking in the ground you have some KE to spare a for larger cutting diameter, thats if really big holes is what your after.