Thanks guys. I was leaning toward the Barnes because I have a couple boxes of the TSX on hand and they shoot very well. On a broadside shot on a cow I think either would drop her pretty quickly.
I watched my hunting buddy a couple years ago in Newfoundland drop a bull moose in its tracks hitting it in the shoulder with a 180 gr TSX. And it never got up.
Mine with 180 gr Sierra Game Kings traveled about 50 yards before piling up. But I shot for the lungs and not the shoulder.