I think the 270 WSM is pushing to much velocity for that bullet, it is causing rapid expansion and quick deceleration. Slow it down a bit and it probably wouldnt have any problem penitrating that jug. JMO. I have used accubonds in a 338 mag on milk jugs, it flattens them, and you deffinitely wont find a bullet. But then again I just re-read your post and you stated it was at 300 yards, it should have slowed down plenty at that range. I havnt a clue what to think now. I have always had good luck with accubonds but I also handload and dont use factory ammo. I wouldnt think that would have anything to do with it either, it is the same bullet regaurdless of who loaded it.