If the M11 is a staggerfeed rifle, meaning the magazine stays attached to the action, then, yes, it will work.

The spacing between the action screws will determine if it will work. I believe that the DuraMaxx is only fitted to the 2nd generation (4.275" spacing) actions. If your action screws are 4.4" center to center, and the magazine stays with the stock when the action is removed, then it will not work.