Howitizer was the best name i could fit to this instructable, its simple, not very accurate, but it may be good for bombardment, with a lot of them.

Step 1: Parts

These are what you will need
Add more orange/whites if your ram(last step) wiggles, and comes loose

Step 2: Supports

Make 2 of the deign shown.Step 3 will show both of these

Step 3: Supports 2

This is pretty much the main step , almost everything connects to these parts!

Step 4: Connecting-Connection

Add the Yellow rod to the current model.

Step 5: Ram

This is the most important step, do it very carefully.
Connect the Blue to the Orange, and add it to the Support, as shown,
Add the rubberband to the end of the ram, to the front support
Add a orange connector to the the yellow rod, next to the front support