I decided not to use one on my 590A1 because you have to leave one of the receiver screws that mounts the side saddle slightly less that optimum tightness or you can lock up the action. This warning was according to the installation instructions so I didn't even try. Bought the buttstock holder instead. However, stay away from the "cuff" style buttstock holder and get the one with the velcro straps to secure it.