I had heard from a reputable acquaintance of an older 180X from a 300 mag failing on a close range elk. It hit "keyholed". I spoke with a Barnes tech ( way back in the 90's) and his opinion was that a long bullet ( of any make) hasn't "settled down" yet, under 100yds for sure. It leaves the bore "slightly yawed" ( like an arrow from a bow) and this "may" have caused it. OK, good theory...fast forward to 2007, I was using the 100TSX from a 257 Weatherby, it was humming too. I shot a Black Hawaian ram around 80yds but the brush deflected it a bit, and he got up and was moving off. I circled around said brush and got a 50yd broadside shot. Bingo, it killed him, but my entrance hole was a fine "keyhole". So I believe it. This load shot bugholes off the bench at 100. So, for myself, I think these up close "failures" have more to do with length/stability,etc than the actual design. Just a thought. BTW, I still use both Partitions and Barnes ( and will use the 358 Hammer soon!) I did use the 300 winmags for small Texas hill country deer with the Sierra 150 Pro Hunter. (They came in Federal Blue Box factory loads!) I wanted a "bomb"...what I got was perfect, Partition-Like performance! It amazed me. So, for deer, that's a good bullet too! Have fun though, enjoy yourself out there!