Comus gun ranges shrink from theory to combat

What were realistic engagement ranges for Comus-class guns when period fire control could not exploit their theoretical maximum reach?

As a rule of thumb, use about 75 percent of maximum range for plausible hits and about 50 percent for genuinely dangerous combat fire.

The theoretical ranges of the 64-pounder, 7-inch, 6-inch, and 10-inch muzzle-loading guns exceeded the distances at which period fire control could use them well. A practical rule of thumb puts plausible hits at about three-quarters of maximum range and very dangerous fire at roughly half. This distinction keeps impressive range tables from being mistaken for effective combat performance.