does anyone have any experiance with those recoil reducing mercury filled tube, or the butt-plate things that have the piston in them (danuser counter coil recoil reducer) that claims to take up to 50% of the recoil away. Are the effective, would like to reduce recoil in one of my larger cal. guns so i can shot it more than 7-8 times at the range, but dont want all the noise of a break