I love my two smoothbore fusils, I have a half dozen custom flintlock rifles that are great shooters, the reason I don't shoot them as much as I do my smoothbore flinters is because they are getting too heavy, age and health have taken their toll on this old man.
However, fair discloser, while good quality smoothbore fusils, muskets, and trade guns are accurate at shorter ranges one, shouldn't expect 100 yd. rifle accuracy from a smoothbore using patched round balls, both of my fusils will virtually stack balls at 25 yds, shoot within 4" at 50 yds., and will keep all shots within an 8" paper plate at 100 yds.
Shot patterns when properly loaded can be as close to modern shotguns out to 40 yds. which makes a smoothbore an excellent hunting gun IMHO.