I really like a 180gr hardcast bullet from hornady and for the bear that might be the best , Used on hogs alot but for a big catit would be a barnes x bullet like in corbons dpx and several others. It will give deep penatration and typical twice the diameter with no loss of bullet wieght. Most companies now load this round under there house names but if it is a solid hp copper bullet it is a barnes x type. I would not take the sig. Only a revolver with heavist loads you cam get.