This was previously glitched but has now been patched.
The CROSSBOW is a crossbow that can be equipped to the LIGHT CLASS.
This weapon is unlocked from the start so you can create your own class with it or you can also find it on one of the default classes called "LIGHT LOADOUT".
Typically the crossbow takes about five seconds to reload but at level 22 you can unlock an attachment for $80,000 that improves reload for the crossbow and you can buy a perk at 27 for $5,000 that also speeds up reloads.
When this is patched just kill 100 human or bot players over any amount of matches with the bow. Kills on zombies don't count.