With any gun be it rifle smoothbore or even a bow, for deer hunting, consider that you must be able to hit, offhand, a 10" paper plate every time at whatever range you choose. If you can do it at 60 yards but not every time at 70, then 60 yards is your maximum range, just for example.
For moose, your target can be a beach ball, so your range will be further, but your charge must be sufficient to completely penetrate the critter, ideally. With the round ball, it is my experience that upon contact, the ball pierces the skin and pulls a plug of hair into the hole, effectively plugging it so that there is almost no blood trail. An exit wound is almost crucial. As an example, I shot a moose with a Brown Bess musket having a .75" bore using a .735" patched ball and 100 grains of powder. The range was paced off at 100 paces. The ball smashed the near side leg bone, a rib, perforated the scapula, both lungs, the offside rib, and the leg bone on the offside, stopping on the hide without exiting. The moose had been bedded when I came upon it, and when I shot there was a blast of snow from the offside shoulder. This indicated to me that the ball stretched that hide significantly, yet did not perforate it. Upon impact the moose staggered and dropped it's head. It walked slowly about twelve yards, and fell onto it's side. There was a significant amount of blood in the snow from it's mouth and nostrils but not a drop from the entrance hole. This is just to illustrate the importance of a pass through shot on a less than mortal shot placement.
Obviously, the same requirement pertains to deer, but the ballistics' needs are less dramatic. My own Chambers 20 gauge smoothbore likes 86 gr. FFg GOEX, a .609" pure lead ball from a .600" Lee mould, and a .020" patch lubed with TOW's mink oil. My effective extreme range for deer, as described above, is 85 yards. I emphatically submit that each of us needs to discover their own maximum effective range, and adhere to it religiously.