It should be noted that Crossbows do not break in gameplay, but are instead limited by the amount of ammo that can fired at a given time, before having to be reloaded.
If there is no ammo remaining, the weapon can not be used until more ammo is located. Both the Bow Gun and Crossbow use Arrows.
Bow Gun
"Wooden bow that fires arrows using a trigger string; the winding mechanism has been adapted so that a woman can also pull back the string."
STR: +38/40
DEX: +10
AGL: +4/5
Ammo: 1
Crossbow
"A bowgun modified to be even lighter with stronger string tension."
