Charts don't mean squat!! Get the advice of an experienced crossbow hunter who has actually taken critters the size of buffalo, moose and African Game . Following the advice of somebody who has done nothing but sat behind a computer, pretending to be an expert is not the way to go.

I sugguest you contact Bill Trobridge , the President and Owner of Excalibur Crossbows. He has taken many large animals up to and including an elephant, I'm sure hw will be glad to pass on his recommendations to you. They will definitely be valid recommendations.
You can contact him through the Excalibur Website or forum