You can fire the rocket with your mouth by puffing the air into the 
straw. The firing distant is approximately 25 to 30 feet. Using the pump. 
You will be able to achieve beyond 40 feet, by varying the length of 
the firing straw.

A word of caution,
 " NEVER AIM AT ANY ONE WITH THE LOADED ROCKET "

You can fire the projectile with your mouth by puffing the air into the 
straw.The firing distant is approximately 40 feet. Using the pump. 
You will be able to achieve beyond 50 feet, by varying the length of 
the firing straw.

A word of caution,
 " NEVER AIM AT ANY ONE WITH THE LOADED PROJECTILE "

When I was a kid creating my own toys, I always try to incorporate
 some kind of action into designing the toy.
Since I've started designing the CamTank I wanted to put my ideas to 
work. I use drinking straw as the tank barrel. I can fire a rocket or 
projectile with my month or using a balloon pump. I started the test
 by creating the projectiles and rockets using polymer clay, straws, 
thin acrylic sheet and foil tape.