And Hammer, while you are answering that, have you opened up the piston chamber? I have not tried the pellets you mentioned and have horrid groups, which I ascribed to my not handling (artillary hold and all) the gun correctly. However I am tempted to go in and look at the seal, the groups are so big. I am just wondering how much preload there is on the piston? Not worth going to hospital just to have a look see!!!