Still have my .177 Vulcan mk1, barrel was chopped to carbine length and a muzzle brake put on it @1990, had a tune done then and although I don't shoot it much today it still gets @11ftlb. One problem I had with mine was the barrel slipping back in the breech block so I would lose air at the breech seal. Ended up having to press it back in place and then use the two rear sight holes with grub screws tightened down on the barrel to keep it in place works ok. I remember when I got this thing it was the first nice springer I owned. Glad I still have it!