There is something missing....a mod I feel has to be done to my QB78 pcp converted spike driver. The hammer bounce has annoyed me since I turned up the heat on this rig, and hearing wasted air exit the barrel after the pellet has left is saddening. My AT44 has such a nice crisp snap to it which is hard for me to figure out what I could do different to the QB as I dont remember any debounce system in that setup on that hatsan. Now I call it the hammer stop, which is the steel dough-nut the hammer slams into after driving the valve pin foward, The AT44 has a brass dough-nut? This is just an idea with no evidence of it making a difference on the QB but if you tap two steel ball peen hammers together face to face they bounce with little effort or force. Tap a pall peen hammer and a brass hammer together?.... you get bored and go mix another drink . Does machining a brass hammer stop sound like an experiment to try in the QB to anyone or has this already been done?