K'nex Marble Shooter

I made a semi automatic marble shooter that I wanted to share. It has a capacity of about 16 marbles.
Base








The first step is fairly simple.
Main Body

















This is where it gets confusing.
Firing Mechanism




This part is also simple.
Extras

This is a stand which I find pretty useful.
Final Product

It's finally finished. When firing try to not pull for too long as it might result in marbles spilling out.