I think perhaps a 140gr. TSX at 2,900fps or a 160gr. TSX at about 2,700fps should work OK and either would leave a blood trail from the far-side rib exit hole.

My own opinion though, having never shot one, would have me start in on them with a 9.3 of some sort, 57, 62 or 74mm varieties. I've read & heard here, they are a bit tough, although smaller, kinda like a Rocky Mountain Elk - that's tough.