I did a few mods to my Hatsan Nova. Nothing extreme I just changed the aluminum bottle to a CF bottle and exchanged the 23" barrel for a 19" barrel. It's shooting 18gr JSBs at 905 fps. For some reason it's wasting air, but it's not affecting the accuracy of the gun. The top target is when I was zeroing the gun, the middle target is 10 shots at 35 yards. Remember I shoot standing using the Caldwell Magnum Fieldpod in the picture.