Mike,
The concept of not enough "penetration" and then not having enough velocity to "open up" are two concepts working against one another. As any bullet begins to open, it's doing nothing more than having it's brakes applied. So for a rapidly opening bullet design to be driven fast enough to penetrate deeply, it typically has to be driven much harder. Sometimes I think that a measure of a bullets penetration would be more accurately described as a bullet having standard or anti-lock brakes? The newer bullets (regardless of caliber) are far better than their predecessors were at penetrating and expanding when timely, rather than at first contact. And then also having cores and jackets hanging together when slowed down by encountering heaving structures. That last is of no small import to hunters. Who regularly encountered core/jacket separation in bullet designs of years past. Apparently, even the cavity becoming plugged while passing through clothing or light barriers has been improved. That's why though I'm very new to the 9X19, I'm not overly concerned about running the 147 Winchester SXT? But that's just for me!