Sorry... Too simple...
You must be pretty new to flash yourself... But you should try to do a tutorial for actually moving a bullet with actionscript, I did manage to add a bullet to my project before, but I lost the project and will never fully remember the shooting script. I had a shooting type that lets the bullet whiz out of gun(2d view) and it worked just like thing thing shooting. I just need to find a shooting tutorial that gives me the right shooting at an angle script.
MAN OH MAN DO I HATE USING COS, SIN, AND ATAN!!!!
I suggest you to make a tutorial for a moving bullet, even if its just shoot em up style.