Well, I can definitely say that did restore the rifle to it's full operation plus some. It's whipping out the Stoeger X-Speeds at just under 590 fps. They are only 5.6 grains but that is still just a bit better then it was stock (+50 fps) and much better (+150 fps) after the attempted pump cup mod. I also noticed that I can increase the fps about another 50 points with 12 pumps as opposed to the normal 10. I'll keep it at ten though as right now it shoots just under legal with normal 7.3 grain HP. Valve plug is a cool mod!