disco based Magnum airgun 15.5 tube cut to 10 1/4″. stuffed with magnums new hot disco valve and huma reg with plenum. added my old disco single shot breech and 24″ barrel homemade ldc. prod trigger group, with made up other crap for stock. shooting .177 jsb 10.3 930 fps. oh .004 clearance between bottle and barrel. Dropped reg to 90 bar shooting 10.3 880fps.