Cornelius - I believe that 40 yds is about the limit for the effective killing range of a crossbow.
From Petersen's Hunting magazine: "A modern hunting crossbow sighted in at twenty yards will impact its arrows approximately twenty inches low at forty yards, depending on their weight and flight characteristics."

So with open sights, a drop of 20" from 20 to 40 yds is pretty dramatic. And beyond that it gets even worse. So, as you put it, 'any moron" would have to be pretty lucky to hit anything past 30 yds, let alone 40 yards and beyond without practice.