Yeah I thought that, the 870's receiver ways a ton compared to modern alloy ones. I guess it depends on each guns exact configuration.They are both pump guns, with absolutely no recoil attenuating attributes. With the same shells, and the same weight and fit, they should recoil the same, but I believe the Winchester is lighter because of the aluminum receiver. Therefore, all else being equal, the SXP should kick more. Rarely is all else equal however.