...

[Adeodatus]

...

[Will Goes Boing]

...... are you serious?

[PositiveInfluence]

Assassin's Creed FTW

[rgray]

Good question. It does not fall under 12020 PC as defined below:

(8) As used in this section, a "ballistic knife" means a device
that propels a knifelike blade as a projectile by means of a coil
spring, elastic material, or compressed gas. Ballistic knife does not
include any device which propels an arrow or a bolt by means of any
common bow, compound bow, crossbow, or underwater speargun.

[Notorious]

It is not a firearm under CA state law. Firearms are defined as devices who use an explosion (ignition of gunpowder) as the propelling force to eject a projectile. Therefore, airguns, airsoft guns, bb guns, paintball guns, crossbows, etc. are all not categorized as firearms in CA.

Check your local ordinances though. Those can vary greatly.