If anyone is curious on the process. This is how I did it. It would apply to a fair amount of other synthetics with stabilizing cross braces as well. I used the 6” SRS Arca rail. I wanted it as close to the mag well as I could get it. Pulled the stock apart. Found and marked where I wanted to drill. Cut out the crossmembers with a dremel. Drilled holes for mounting screws. Make sure to not interfere with the metal skeleton, clearance could be an issue if you try to drill too far back. I then scuffed up composite on inside. Installed rail with t-nuts to depth I wanted to work with. The composite is very thin in this section so I chose to install the rail first, but not wrench it down, then I went back and filled in the voids with epoxy to really lock in the t-nuts. Put back together and voila! LOL