(I think your original post, and my response, were lost in the server upgrade.)
As I understand it, the advantage of the Minie ball in the rifled musket over the paper patched roundball in the smoothbore musket is in accuracy of aimed fire at longer ranges, and retention of velocity and energy at longer ranges.
I would not think there is any difference in the speed of loading. Within 50 - 70 yards or so, there should be little meaningful difference in accuracy.
But double the distance to 150 yards, and the rifled musket Minie combination is in its own league. Double that distance again (300 yards) and the rifled musket /Minie is playing by itself. And it could do so at even greater ranges.
This is due to the poor ballistics of a round ball, the better ballistics of an elongated, heavier bullet, and the advantage of rifling.
Obviously, the round ball was dealing devastation to deer, elk, moose, bear and men long before Minie invented his bullet. The Minie just did it better, at greater range.
Unfortunately for the soldiers, the military tacticians of the day did not fully grasp this fact.
Others should be along who will add to this, or maybe say that I don't know what I'm talking about, and show us why. :grin:
Fact is, I get educated, and re-educated, every day on this Forum.