the op hasn't specified, ie: most ethical range to shoot at game, or at what range is the smoothbore still lethal, and that sort of thing. So I'll tell you the tale of my first moose kill. In 1979 I was hunting in the "Primitive Weapons Zone" in British Columbia, using a Brown Bess musket of .75 calibre. I was shooting a tightly patched .735" pure lead ball over 100 grains of FFg Goehart Owen black powder. I came upon a moose that had just jumped out of its bed and stood broadside to me at a paced 100 long steps. My ball struck perfectly, breaking a rib, both lungs, a scapula, another rib and stopped on the off side under the hide. The ball expanded to about the size of our dollar coin, and the moose staggered another fifteen yards before going TU.
Knowing your own and the guns effective range takes lots of practice, and in this case paid off in spades. I have said before that you and your gun's effective range is that where you can hit a pie plate every time. In the case of a moose, the target is a beach ball or garbage can lid.