This is very useful circuit diagram because we all love to make different types of sound generators .Today I'm going to introduce you a machine gun sound generator circuit diagram.Free Circuit Diagrams 4U has already given you different types of sound generators with our previous posts.Actually this machine gun sound generator operates with 3V power supply.And also here I have used common IC UM3561.To amplify the out put signal I have used  BC548 transistor.I have attached this circuit for my mountain bike and enjoy with this a lot.Hope to see you soon with another post