Except as otherwise provided in section 3-7-5 of this chapter it shall be unlawful in the city, for any person, firm or corporation, to sell, give, lend, or in any way furnish or cause or permit to be sold, given, lent or in any way furnished, to any person under the age of eighteen (18) years, any cartridge, shell, ammunition or device containing any exploding substance, designed or intended to be used in or fired from, any gun, revolver, pistol or firearm. (1960 Code)