The Duramax works with the long action staggerfeed. It could be modified for the centerfeed by fitting the CF mag to the stock. I got a standard long action staggerfeed stock to work with the CF by gluing popcicle sticks in the mag well to hold the mag in place. I cut the front and back stick to the length of the "L" bracket and the front cut to the lip of the mag box. Additional stick were used along the side to hold the box in place. It work well for my 270. and I could still return the stock to SF configuration if I needed to.