It shouldn't be surprising to most riflemen that a lead round ball is an effective projectile, because they were used successfully for hundreds of years to kill game and win wars. But most of us grew up reading the writings of guys like Jack O'Connor, Warren Page, Roy Weatherby, etc., who extolled the virtues of streamlined small caliber bullets at high velocities. Just about every new and improved cartridge was a belted magnum that was supposed to be faster and better than the old outdated .30-30 or .30-06.
I started out with high power centerfires, and it was impressive to be able to shoot groundhogs at extreme ranges of 400-500 yards or more. They also worked perfectly on deer and other game, so long as you placed the shot well. But after about 10 years of that, it just seemed too easy. It was unsatisfying to wait all year for deer season, and then have it all end early on the first day by simply lining up crosshairs on an unsuspecting deer, squeeze the trigger, then gut and drag. I felt more like a sniper than a hunter, and switched to using a flintlock rifle for all of my deer hunting for many years. At first, I wasn't sure what to expect. It was more of a challenge to intentionally handicap myself with a single shot and open sights only. Then there is the uncertainty of hoping the gun would even go off. There was a learning curve involved to just be reasonably sure my flintlocks would fire in damp or rainy weather. And after years of seeing ballistics tables and being told by "experts" we needed a couple thousand foot-pounds of retained energy just to cleanly kill a deer, I had some doubts about a .45 or .50 cal. roundball at around 1900-2000 fps, because the numbers said it was anemic compared to even the lowly .30-30
I killed my first flintlock season deer with a .45 cal., and it dropped after running about 20 yards. Then I switched to the .50 cal. because the .45 roundball was only about 128 grains and the .50 cal. ball was about 50 grains heavier. So the kinetic energy numbers were better, but still quite low compared to most centerfire deer rifles. Naturally, I wanted to drive them as fast as I could while maintaining good accuracy, so I used fairly heavy charges of FFG, and always wanted to use Swiss powder since it gave better velocities than the DuPont or Goex. I even used a small wad of hornets nest material between my powder and the patched round ball, because I read that gave up to 100 fps higher velocities. I also considered getting a .54 cal flintlock to have more killing power, but the dead deer kept piling up, so I didn't bother. I kept getting these fast clean kills that seemed all out of proportion to the energy of my .50 cal. round balls. I saw other hunters often needing multiple shots with their 7 mm magnums or .300 Win. mags, and my deer were all dropping in their tracks, or running 20 yards or so before piling up. Best of all was that this was more like hunting than being a long range sniper.
Of course, I wasn't gut shooting running deer, but doing my best to get a clear shot that took out the top of the heart. Most of my shots were broadside, or nearly so, and I quickly noticed that very few of my round balls made an exit hole. Instead, I would almost always find them under the hide on the far side, flattened like a pancake. With that much expansion, they did plenty of damage. When you punch a large hole through both lungs and the top of the heart, the deer's blood pressure drops to zero right now, and that deer is dead on its' feet.
Still, I wished I had an exit wound in case I didn't make a perfect shot, so I would have a good blood trail to follow if necessary. I mentioned this to an older guy who was also a muzzleloader, and he advised me I was driving my roundball too fast, and that they would be much more likely to penetrate completely at lower velocity because they wouldn't expand so much. He was absolutely right, and it made little difference in trajectory at deer woods ranges anyway.
It is very hard to generalize with round balls. In many respects, a .25 cal. round ball weighing 24 grains is very different than a 12 bore round ball that weighs around 600 grains. Most often, round balls are pure soft lead, but sometimes they may be cast out of a harder alloy, which will naturally help with penetration. As you go up in caliber, the weight increases exponentially, and a heavier ball will carry further, retain velocity better, and penetrate deeper. Nobody in their right mind would want to use a .32 or .36 caliber squirrel rifle on a large bear, but large caliber round balls have been used to effectively kill bears, moose, buffalo, and even elephants. If I see a great deal on cast round balls at a gun show, I will press my thumb nail into one to get an idea if it was cast of relatively pure lead, or something like wheel weights or Linotype alloy. When casting round balls out of scrap lead, it can be difficult to know if it is pure lead or some unknown alloy, so that may account for different performance. For hunting, I just use Speer swaged lead round balls, because I know how they behave. Loaded correctly in a good barrel, they are extremely accurate, and they kill game clean and quick. I no longer feel handicapped when I use a flintlock for hunting. I simply feel more like a hunter than a shooter.
