single shot rifles are inherently more powerful than muzzle loaders, with far greater range and typically better accuracy...follow up shots don't really enter in the equation
thats one cartridge...try your muzzle loaders vs. the tiny .243Thats not what I've heard and read about the new 350 Legend cartridge thats gaining popularity.
Long range magnum muzzleloaders in 45 and 50 cal far outclass and out range it.
Faster follow up shots are better. I don't believe in second shots but they can make for a quicker and cleaner kill sometime. Where I hunt second shots would be hard to make, I hunt in branches and swamps and most of the time you can't see over 25 to 30 yds. The tress and brush make a second shot a almost impossible. Therefore, as a professional I only shoot when I believe I can kill the prey with one shot. Even when I hunt open areas I shoot for a one shot kill. To me one shot kills make for better hunting, separates professionals from blasters. Don't get me wrong sometimes you must make multiple shots to bring the game down, but I don't plan for multiple shots. I know some don't agree with all this, but I am old and my father taught me to kill with one shot. His father taught him that lesson from the old days when ammo was to expensive to waste.