I killed my elk this year (approx 475 lb cow) at 90 yards with my CVA Bobcat. The load was a 370 grain T/C Maxi Ball and 80 grains of 2F powder. I hit her in the back, which dropped her, and I had to make a point blank shot in the base of the skull to put her down for good. I have no experience with what this bullet would have done on a rib shot, so take this info for what it is worth.