I have shot three, all with a 458wm DR. I used 500 grain Woodleigh solids. Two I shot well with both barrels and things ended very quickly. One I shot poorly as I was both huffing and puffing and rushing. Didn't realize he was quartering to me some and was off on the shot too and hit him behind the lungs. Second shot creased his briskett. He took four difficult hours to catch up to. He was hurting but still plenty able to get to his feet when we cought up to him.

I agree with OzHunter on rifle choices. It seems to me that the ideal from an efficiency standpoint would have the tracker carrying your scoped bolt in case you can't close the range on the buff you want. Switch out if you need to and make the shot with your scoped bolt, then switch back for the approach. But a dead buff is only part of the hunt. I have passed up shots I wasn't comfortable making with my DR (and from the earlier part of my post, should have passed up another!) and declined to take the shot with my 375H&H which the tracker was carrying. I would rather try to get closer or try again the next day. Don't ask what I'd do on the last day of the hunt!

JPK