Hi Gene, thanks for take some time to respond, at this moment im just are a backyard plinker, i forget comment that i have a TF-99 .22 too, and make the same job in the piston, it have the same power plant that a B3 in fact the inner diameter of the cilider its the same than a B3, these guns are really awesome in accuracy, and in case of the TF-99 the power than could make, im just figuring that the speed of my TF surpassed 900 fps with high grain pellets.