dunno...
thruthevitals post showed a link of a hypershock that appeared to get stopped by a rib
like I said, don't want to debate fixed vs mechanical
just a thought....

BTW I'm shooting at 65lb @ 29" draw, Dominator 300's out of a Buckmaster
i figure the KE @ about 55 lb... I wasn't worried about penetration, just the performance of the broadhead