Anyway, I was looking at all these spring guns, as they are both the cheapest and simplest and I want to have a full understanding of how it works and to be able to learn how to take them apart and modify them, and my question is if you sealed the area where the main spring lies, and added an O ring pair to the piston connected to the spring, could you inject some pressure and replace the spring with air? It seems like it wouldn't wear down like a spring, and you could easily adjust the power by pressure. Here is how I understand it would work:
![Image](http://i.imgur.com/MkHmy34.png)
Is this something that could work, or if not why or is there something I can change even further?
Also, maybe I could experiment which gasses are better- my guess is the harder to compress the better it performs?