I agree with elmerfud, as I have an S4oo classic .177 and find that the sweet spot for my gun is between 145 bar and 120 bar where I get 44 really consistent shots, there is no point in filling your gun up to 190 bar, as it will be down on power, and the next 20-30 shots will be increasing in velocity until they hit your guns sweet spot, as the S4oo is not regulated. You need to fill up with air and fire say 100 shots over the chrono, and record results so that you know roughly where you are getting your most consistent shots. Hope this helps, Mark