I shot a yearling doe with a 58 ball over 75 grains of 1.5F OE at about 70 yards. In many ways, this was a perfect broadside shot on a quartering away animal. The ball went right through the heart, cause damage to the lungs, exited through the front quarter and the animal made it 20 yards or less with a blood trail that wasn't hard to follow through the waist high grass. There was little left of the heart except framing for the hole, in fact. However, when I skinned it I was amazed at the amount of bloodshot meat on the torso. Not what I expected of a round ball that likely wasn't doing a whole lot more than 1250 FPS or so out of the muzzle.
Maybe it was just that the doe was small, but I lost a lot more meat than I would have guessed with a round ball. I may choose to use a 50 cal with PRB next time. Prior to this year, I had been using a 54 round ball with 110 grains of powder.