I put about 80 rounds through my new 45 Shield and the guide rail came apart. I contacted S&W and they are sending me a replacement. I can't fault their customer service although I would prefer not to need it. I mentioned the stainless steel rail that is available and he said it put excessive stress on other parts of the slide and is not recommended. I am curious how a stainless steel rail will make the slide function easier and still causes excessive fore on the slide?