BSA Ultra .22 cal shooting JSB 18.1 @ 600fps. 8 inch barrel, 4.5mm transfer port, Huma regulated. I built this rifle for confined spaces. Really a hard hitter for such a small platform. I really love shooting this thing. Sometimes while I am working on customer's guns I need a break, so I take this little gem out for some general shooting, or the occasional starling. Hope some of you die hard BSA guys like it! It also has a custom molded grip I made to fit my hand like a glove. Peace, love, and airgun shooting!