I would think Sierra knows their producte pretty well:

"While they are recognized around the world for record-setting accuracy, MatchKing® and Tipped MatchKing® bullets are not recommended for most hunting applications. Although MatchKing® and Tipped MatchKing® bullets are commonly used for varmint hunting, their design will not provide the same reliable explosive expansion at equivalent velocities in varmints compared to their lightly jacketed Hornet, Blitz or Varminter counterparts."
Sure, I have ended lots of woodchuck and many coyote careers with a #1410 Sierra HPBT MK (0.224"). That's not deer.

Though, to the original post, no hunting bullet of any composition or design works very well if it doesn't hit the animal. And, conversely, even a FMJ that had no real expansion will kill if put in the right place. But why not use a purpose built design to ensure the cleanest, fastest kill even if Murphy gives you a "wet willie" in the ear during the shot? Or the deer moves, twig interferes, wimmies and wobbles, etc.

The race is not always to the swift nor the contest to the strong . . . but that's the way you bet. ;-)