A friend of mine just recently purchased a new M1A and he was having a problem removing the stripper clip guide and putting on the side mount scope block in its place. Ok not an issue I told him to come on over and we would do that in a new york minute. Anyway i started to remove the set screw with my allen wrench and no go. i got to looking in the mount hole and my buddy said (i tried to get it out but it wouldn"t budge). Ok not a problem got a set of easy outs for scope screws and small set screws. When i got to looking at it under a strong light i noticed there were no threads on the mount i had in my hand or the one on the rifle it is a roll pin. So if you do any new M1A scope mounts just get your 5/64s pin punch and tap it out. Hope this helps somebody in the same boat. Yall keep shootin while i reload. I have an old M1A and it is threaded guess the newer models are roll pins.