although power went up notably after tuning, I couldn't allow the gun to ship with that chamber in it. Tim at Mac-1 graciously offered to exchange the piston and chamber for a good one.. so I sent it off to Tim for the swap. As soon as I get it, your -97 heads home. Regards, Russ
BKL mounts..11 + 14mm
http://www.airgunshow.net/Bestunes.htm