I had a smoothbore .44 cal. flint lock gun at one time. It was fully capable of head shooting snowshoe hares out to 50yards, with a patched round ball.
I currently have a 20 bore, smooth bore flinter that has a standard choke at the muzzle. Hitting at 50yards (keeping 5 consecutive shots on paper) and further is a stiff challenge for this gun,
however it seems to shoot quite well at 25 yards with patched round ball. This gun puts out amazingly dense and close patterns, even though the choke is barely tighter than IMP Cyl.