It happens. That is why I always advise averaging out results. Too many people shoot one and become and expert and condemn product others are extremely happy with.
I had the same thing happen with a Fallow buck at 75 yards quartering towards me. The bullet entered the shoulder with intent to drive through the opposite lung, perhaps clip the heart on the way through. The buck jumped like a bronc and fell dead. When I examined it, the 90gn Sako SP factory load had performed a U-Turn and exited out the throat (almost in my direction) with a 4 inch vertical tear.
That .243 never let me down and the buck was in the bag but that bullet??? After killing a few more animals I realized it was just one of those things. Get on with it!
