Saw the aftermath of a 139 hornady from a 7 Rem Mag on a nice desert ram earlier this month. The ram was DRT at 178yards and the cape damage at the exit seemed minimal as we skinned it for a full body mount. I'd go with whatever was most accurate in the rifle if just for the confidence factor...
First hand experience can be rare around here. Only one I saw shot with a rifle dropped with no exit from a 7mm 140 ballistic tip.
