The medieval military crossbows fired a short, heavy bolt, which would penetrate stout personal body armor and equestrian armor of the day.
I have the iron head of a crossbow bolt from the Thirty Years War, which was retrieved from the thigh of my ancestor, a commander for many years of that war, on the German side.
Back to the present, I just gave a birthday present to a son-in-law for his hunting cross bow: a Bushnell 2-7x32 crossbow scope with a crosshair and dots for the drops at further ranges. The modern crossbow shafts are much lighter than the oak ones of old, but they still are much more than necessary for most big game, due to the velocity, shallow arc, and accuracy. A heavier shaft, though moving slower, is like the heavy slow-moving bullet from a .45-70; lots of penetration. Even a 30-lb longbow with a cedar arrow and 140-gr two blade broadhead will surprise you with the penetration.