My hw100 22cal fac was originally shooting at 850 fps with 18.13 JSB pellets . I reduced the hammer spring tension in quarter turn increments until I got the best groups with these pellets . I have found that it likes the 805 fps velocity . I did a lot of shooting to come up with this velocity for the best accuracy , I went as low as 750 fps and then worked my way back up to where it was grouping the best. This is a very easy rifle to adjust useing a ball end allan key. My groups went from 1 1/2 " to 3/4" at 40 yds.

Much joy now Torrance but still looking for better. Suggestions appreciated.