I am puzzled that the 175 Hornady RN would come apart. I would have guessed a larger expansion diameter and shorter penetration than the spire point.
That was my thinking as well. I was very surprised that there was nothing left of the bullet.
I’m not surprised all that much as I have seen their RNs wear pretty thin even in flesh and in even larger calibers. On the other hand, consider that you don’t get penetration from nothing, and that bullet apparently tied for second-place penetration. What the bullet finally looks like matters not if it works reliably and consistently to get the penetration and damage needed. The Sierra is no surprise to me either as they use a decently hard core in their heavier game-type GameKings in many/most calibers. Sierra bullets work well under the older traditional rules of bullet selection (they “burn off” like a candle so you need heavier/longer bullets for longer penetration requirements). I believe they have suffered somewhat from internet ‘bullying’; they don’t quite make the cut with the ‘in crowd’.
