For the purposes of Sections 9.60.040 through 9.60.070, the term “firearm” means any gun, pistol, revolver, rifle, automatic pistol or rifle, shotgun, or any other weapon of a similar nature. The term “firearm” shall not mean “air rifle,” “BB gun,” “air pistol” or “air gun,” or similar instrument described in Section 9.60.020 of this chapter. (Ord. 77-11 § 3(E), 1977.)