The shoulder stock is adjustable as its built by Smith and Wesson. There are 5 or 6 locking lengths positions so you can set the length to whats best for you. There's a spring loaded lever on the bottom of the stock to lock it in place at each separate length. You may know all that but I put it in here just incase you dont. So now in Mass - just like here in Conn no one can buy a adjustable shoulder stock. So a pin has to be added by Smith and Wesson to lock the stock in it's longest position. Removing the pin has no effect on the shoulder stocks NORMAL operation meaning that without the pin you can adjust the shoulder stock to any length you want. I've seen pin removal videos online and it looks simple enough. It has no negative effect on the rifle at all. Believe me.