I bought a cheap flinter to try hunting with one. I sighted it in at 50 yards and practised enough to be pretty confident at anything under that. I crossed the lake and slipped up to the spot I planned to watch from. A nice buck came slipping down the hill thru some cedars one toe over. He turned, headed my way and I was already set. He reversed his course and I thought maybe he had gotten a wiff of my scent. He stopped in the clear at a little over 60 yards quartering away. I squeezed the shot off and when it went boom, it looked very good. The smoke cleared and all I could see was a light brown patch on the ground where I had shot that I had not seen before then. I was all excited. Not only did I get my first flinter buck, but he dropped on the spot. I wiped the gun and reloaded. When I got to the spot, it was a scrape on the ground, not the deer. Now, I never saw the deer run because of terrain and the smoke. I never heard so much as a twig break after the shot, but I was hunting on the bank of a lake and the shot noise had set off a chain reaction of ducks and geese to go with the noise of the shot. I started to circle. No blood. I walked all of the trails down that side of the lake. Not a speck of blood found. I circled back to where I had shot. I went to the top of the hill and checked the trails coming out into the feild. I slipped up on a doe but would not shoot because I was sure I had hit that buck hard. I started down a road the goes around the lake looking for sign the deer had crossed. It was getting dark and I was 1000 yards or so from where I had shot on the back side of the lake with no luck. I decided to wade thru the brush to the end of the lake and work my way back to the boat and go get lights. I found him on my way back to the boat where he had leaped about a 15 foot creek bed and died. I found him because I am too stupid to quit when I am sure of the shot, and because I was looking for an easy way across the ditch so I could get back to the boat. There were a few drops of blood where he fell, but I never did see a single speck on my way from where he fell to get the boat. The ball entered near the back edge of the ribcage and exited just about where you would want to hit one standing broadside. The shot was not that far off the mark, but it was a little far back. I had mis read the correct angle he was quartering away I guess. The deer had traveled about 400 yards thru a multi-flora tangle you have to be in to believe. I am an experienced tracker and I am hard headed enough to spend a long time looking for a deer. It was still luck and persistance that recovered that deer. .495 round ball over 70 grains of Graf's/Shuetzen out of a carbine. The ball went all the way thru but he did not bleed as he ran.
If that had been an REAL bullet, the damage would have been greater and the exit hole larger. If it had been a Maxi-ball, same way. Both of them would have offered a much better chance of trailing the deer to where it dropped. If it had been the Lee Target Mini, he would not have gone half that far most likely, and the exit hole would have been much bigger. Had it been a Hornady 385, most likely the deer would have died within 100 yards of where he was hit and trailing him to there would have been no problem.
On a prefect broadside shot into the heart lung complex, the roundball will usually exit and even if the wound channel does not provide a good trail, the nostril blood does. On hits that are less than optimum, the roundball often does not exit and often does not offer a bloodtrail if it does. Combined with the smaller wound channel allowing the game to go farther before they drop, this is a recipe for losing injured game hit with a fatal shot.
If you are willing to wait for the perfect shot with in a range that you can precisely place your shot, the 50 roundball is a good hunting tool. If you are not willing to wait for the broadside boiler room shot or plan to shoot at 100 yards or greater, then put a conical in your gun. Historic accuracy be darned.
I hunt with PRB's over 70 grains of 3f black in all my 50's. A couple handle more powder well, but I target shoot with 70 and the guns are all very accurate at that level. I will not shoot at a 100 yard dear with that load. I try to stay at 60 yards or less with caplock and 50 or less with the Flinter. The 60 yard shot I took at the buck was a very long shot with the flinter for me. If I wanted to shoot at 100 yards, I would be shooting the Lee Target mini in a couple of guns, the Lee REAL in a couple, and the 385 Hornady in one. All of them are better deer bullets than the roundball at any range. Past fifty yards, they are much better deer bullets. At 100 yards, there is no comparing a round ball to any of them. They are in an entirely different class.
A dedicated round ball gun for deer should be at least a 50. 54 or 58 are better. The shots should be kept to the range where you can hit the bottom of a soda can off hand regularly. When you go past where you can keep them in a 6 inch circle regularly, then you are shooting too far for roundball.
Down off soap box. Don't put a beginner in the place of wandering around hoping to get lucky and find the deer they are sure they hit. Put a conical in their gun until they decide they want to use roundball and you are sure they know what that means.