I guess I've always considered the 6 too small to be greatly effective on whitetail. Mine does great on groundhogs with the Nosler 70gn Ballistic tips. Perhaps be ok, but if you can move a heavier BT to open up effectively, I'd recommend the 90gn or so. At 90gn, fps is crucial because of the short barrel, you should really use a chronograph to confirm you are reaching the velocity to open effectively. In the 85-90 grain range there is a large selection of great bullets available from many manufacturers, the trick is, you've got to move them fast enough to open up. I hope this helps some, but the twist will help determine what weight you can get stabilized.