Can anyone tell me if the current model 4" 686P is considered a round butt or a square butt? I'm a little confused because I know that some guns are round butt frames but are equipped with square butt style grips. I want to order some Pachmayer Decelerators for a 686P (which I don't have in hand yet) but I'm not sure whether to order the round butt or the square butt grip. Thanks a lot. Fleiger