I forgot to ask, if the bullet didn't make it to the boiler room, just went in a "couple of inches and stopped", his second shot obviously performed better? Otherwise, how did he find out of that was all the first shot did? Or did that first shot clip an artery or something and the Moose went down?

My example was from a centerfire experience (Marlin pre 64 336 30/30). Killed quite a few Moose and Elk with that "weak", "outdated", "Can't kill anything bigger than a whitetail" old girl. Upon recovery of that Moose, I found that old Cup And Core had blown into 6 pieces and penetrated approximately 3 inches. That was the first and ONLY time those had ever failed like that from that old 30/30. Might have been a defect (Bubble in the lead). Chit happens.