Changed it from .177 to .22 cal.,did some polishing on the trigger,added a power adjuster(my own design).lightened the hammer,(about 35 grms)cut the hammer spring two coils. with the adjuster in to where the gun will not cock then backed off I am getting an average of 810 fps.for about 25 shots,But boy did the noise level go up.Think I will turn down the fps to about 750 and see if noise level drops some .
Gary