Stock Reinforcment-Different Approach
Hey Frank...great post. After contemplating a method similar to yours I decided on a different approach. I attached a picatinny rail almost the length of the stock fore end (aprox 10" or 11') attached with 3 evenly spaced screws to underside of the fore end of the stock. It did stop the flex of the fore end but I noticed flexing at the stock sides in the area of the receiver and trigger housing. I decided to remove the long picatinny rail and replace it with a shorter rail screwed just forward of the front action screw making sure not to interfere with the recoil lug. The result is I can mount and use a bi-pod with very little to no flex at all. It's not the optimum location to mount a bi-pod but it works. I find when using support other than a bi-pod it's best to rest the stock as far back as possible to reduce interfering with barrel float.
I choose this approach with the idea of a minimum modification other than drilling a few holes in the stock. If it didn't work I could just fill in the holes with epoxy and be essentially back to square one. I did do the filling in the grip etc to beef that area up.