This is what I was trying to do. But when I increase it, the air just flows out of the barrel. It barely gets to 20psi as the more and open it, the higher the psi goes and the faster the air comes out the barrel. There are no leaks in the reg and it must be something to do with the bolt at the top as it properly comes all the way forward and I've never experienced the air to just flow out like this.
Thank you for your help by the way.