Worst for me was a .277 130 grain Speer BT that I tried to use for hunting in the late 80's. I shot 3 animals that fall using that bullet (WT buck, bull, bear) all at ranges under a 100 yards. In every case, the shot would knock them down or stagger them and in each case the animal would get back up and be on the move. Every animal took multiple shots to eventually kill even with shoulder shots. Very little penetration in every case.
On the buck, the bullet literally exploded with less than an inch of penetration. It was a long tracking job. I was young, inexperienced to bullet performance and didn't know this wasn't supposed to happen. That was until my uncle saw the rodeo with the buck and suggested using a Partition, which I did for many years with no problems. I'm pretty sure Speer doesn't make that bullet anymore.
