It seemed the conversation was focused on the load. Other factors can come into play too. For example, if the charge wasn't fully seated (or a heavy conical or sabot moved toward the muzzle, leaving airspace..), a double load (I did this once, talking, during competition...was lucky).
There can be no doubt, however, that marketing and the 'handloading' aspect of muzzleloading can get a newbie into trouble. Although I'm not drawn to the inline muzzleloaders, I have one. I don't believe that some of the really hot saboted loads really buy you anything worthwhile. They should still be considered 100-yard guns. I've gone back to the flintlocks and the caplocks. And the whole concept of load development, in 50 grain increments, with the pellets is insane. Who in their right mind would think this is an ideal method of finding an accurate load?
Hunting skills are still required. Isn't the goal to realize the challenge of the stalk? There is no purpose, and only risk, in adopting the goal of making a .30-06 out of a muzzleloader. If that's what you want, more power to you, just buy a .30-06!
What the numbers do not show is that a .54 roundball on 95 grains of powder, or a 500 gr maxie ball on 80 gr of FFg still has some serious power. Lewis and Clark were hunting Grizzly bears with these kinds of loads (Don't try this as a weekend shooter!)
Muzzleloaders are effective because they throw BIG HEAVY chunks of SOFT LEAD at moderate velocity. This is a combo that is suprizingly effective within 100 yards.
What more could you want, and would it be worth it.
My $.02