I've only killed three deer with a .50 cal PRB, my load was 95gr 3F goex with a .498" ball which was extremely accurate, only recovered one ball, the 3-point Blacktail(6pt eastern) was trotting behind 6 does all in a line right in front of me not 25yds away, I was carrying my flinter, held on his chest a little further ahead than I normally would for a broadside standing shot just in case I stopped my swing as I pulled the trigger, didn't want to hit him too far back, the ball went thru and thru and lodge in the knee on the opposite side, he stumbled, but kept going leaving a blood trail a blind man could follow, he turned and went downhill about 50-60yds and piled up, by the time I reloaded and got down to him he was still. Ball was about ¾" in diameter, the exit hole was about the same size.
The other two I shot with the same load, one was about 90yds broadside not too far from where the 3-pt was killed, he did just about the same thing, turned and went downhill about 50yds and was dead when I got to him. The other one was a 4-pt bench leg (muley blacktail cross) at about 50yds, I was hunting a 5yr old clear cut, he and several other deer jumped up almost under my feet, they went one way, he went another, I did the baaa sound I use to stop deer, he stopped and looked back my way looking over his shoulder as he was standing quartered away, I put a ball thru his shoulder missing bone except for ribs, it apparently was close enough to the spine that it stunned him and he couldn't get back up immediately, but he was trying to get his front legs under him, I reloaded and shot him in the head behind the ear to put him down.
Tim