Hi again , I used what I had available at the time. Used an existing hole in the rear sight bridge and drilled two new ones up front for a total of 3 screws. This is fine for .303 recoil, but if you have a true M10 I am assuming it is in 280 Ross, and would require at least one more screw on the mount, (in my opinion ,anyway). I don't know if those old mounts are long enough to get that extra screw at the back. I'm thinking a good 'smith might be worth his cost here. Let us know how you make out. .....catnip.