you will need 4 bamboo skewers, a lot of elastic bands, tape -electrical works best, and empty pen tube or straw.
Step 2: Secure it up
use elastic bands to secure 2 bamboo skewers together - i cut the tips off the skewers because this is not the ammo or 'bolt'. after this step you will have two sticks of two bamboo skewers secured together.
Step 3: Secure it again
secure it with tape and elastic bands like in the picture
Step 4: More securing!
secure the tube or straw on top
Step 5: Secure an elastic band!
secure the elastic band, to the sides and you are ready, i use more bamboo skewers as ammo! also you can use a bulldog clip as a trigger