Karl I have none experience on cats whatsoever - however been around when dealt with bears and thats where I would start my presumptions - it would be based on velocity - faster (above 2600fps) calibers would be served best with hardest (TSX, A-fr., TBBC...), 2200-2600 medium class (seen great results from 9.3x62 and 74R with Oryx bullet), below 2200 softest - placed wisely (shoulder bones are tough)? Just a guess!