So do you intend to develop a head that will penetrate at those lower KE’s? There’s got to be a point of KE, regardless of head design that it just won’t perform. Also are you looking to penetrate the flat part of the bone, or that thick heavy ridge? In my experience there aren’t too many shot angles that require punching thru the flat part of the shoulder even if it could be done so easily. Are you considering momentum as well? 2 setups with identical KE can have different momentum and thus affect penetration.