Quote Originally Posted by Mach 1.5 View Post
HW55M. VMach match trigger. 15inch .22 cal HW choked barrel. Custom piston. Power 11 ft lbs. Mach 1.5
I see people are able to get 11fpe from the old HW50/55 platform, but my experience with those guns is that this is difficult to improve power much.
That custom piston probably gives a stroke increase?