Oskar,
I would consider 5.6x50R, if I wanted to line a 9.3x72R.The smaller head diameter would make for a stronger liner w/o having to ream the old barrel so thin as to risk messing it up.If your state allows it, the 5.6 with 60 gr Nosler partition bullet will kill a Whitetail as well as a 219 Zipper or 25-35.
Mike