No Fear, the bullet at that range did not blow apart, but judging from the hole it did mushroom nicely. It certainly didn't pencil through. Ol' whistle pig only made it a few feet from his rock.
mtnwrunner, at the elevations I'm usually shooting at, 12000' +, there is usually only a few weeks of shooting before it begins freezing hard enough that they just don't come out to sun on the rocks. I have another place an hour above my house where I am shooting at around 10000', but I can't find the distances. About 800 seems to be all the further I can get there, so I use the elk rifle.