This sounds to easy to be a good idea as compressed gas (air) is very iffy to mess with. Have you priced another cylinder? I believe that the cylinder has the vale gear etc so different cylinders may produce slightly different powers. Although it seems odd have you tried running at 175bar fill. The lower pressure allows your first few shots to be upto speed. If you fill to 190 the pressure can work against the valve gear and actually reduce the power for the first few shots. As an aside have you any experince with slings on an S200. I'm not to certain about the forestock.