I just bought this and love it. Global Sportsman Mossberg 500 / 535 / 590 / 835 12 Gauge Shotgun Stock Buttstock + Recoil Butt Pad + Swivel Stud . you can see what others said about it here http://bridgerguide.com/global-sportsman-mossberg-500-535-590-835-12-gauge-shotgun-stock-buttstock-recoil-butt-pad-swivel-stud/
Petzl Sum'Tec 43 Ice axe
The receiver mounting scheme of our sling and hook loops for the Mossberg substitutes custom-machined Chicago fasteners for the trigger pin. The sling or hook loop is free to rotate about the retainer.