Are you ready to see an amazing invention that is border-line insane?
This guy over here made a completely automatic arrow-shooting Gatling gun using only coke bottles and wood. We would suggest that you steer clear of him if you see him out in the wild. 
The design is actually quite wonderful. 
The coke bottles serve their purpose as pressurized containers. He fills them up using a bike pump or compressor. The pressure is released using a simplistic turning of the lever and powers the firing of arrow from the corresponding tube.
Yes, fully automatic indeed. 
He has achieved that via standard power drill.
This is a close up of the gun at the work. 
With the rotation of bottles, the levers strike the wooden plane at the top of the gun thus firing an arrow.
In action!
He used an ‘okay-ish’ air compressor that reached only 120 psi.
This is what was achieved when he used a pressure of 200 psi. 
We suggest you don’t make one of these at home though.
