I've been working on a simple and realistic bb gun. it was not hard to make, but i have only pictures of the
finished project.
here they are: the instructions!

P.S.
sorry for bad english (in case it's bad)

Step 1: What You'll Need:

-Wood
-pvc tube
-duct tape
-wood glue
-balloon
-decoration tape
-cardboard

-iron saw
-wood saw
-scissors

Step 2: Building and Shaping Your Bb Gun

first you need to make the gun from wood. don't make a slide on it , your pvc tube is going to be the slide ànd the barrel. (it has no slide action)
i made it by glueing different pieces of wood together until it looked like a real gun

Step 3: Taping and Attaching the Barrel

okay now that you have your gun shape,
put the pvc tube on the place where usually the slide is and tape it onto your gun. you may want to add an extra layer tape because it can break if you shoot the gun.

now, cut the inflating part of the baloon off and tape it on the back of your gun, onto your pvc tube.

tape the rest of your gun with duct tape until the whole thing is black
or grey (it depends on what kind of duct tape you are using)

now grab the cardboard and the decoration tape, because we are going to make sights!

first: cut out the shape of sights you want,

second:tape it with black decoration tape

third:add some misc.
for example:green or/and red dots

fourth: you are done making a bb gun, but you need to know how to fire it.

Step 4: Firing the Gun

first you need to put a bb in the barrel.
let it go into the balloon.
grab the bb (still in the balloon) ,
pull the balloon and release it.
thats how to fire it, but please wear safety glasses because it shoots very hard.
i am not responsible for any harm you can do with this gun. never aim at animals or people , and have fun