I've had an SD9 for about 3 months, never even looked at it from the front until I saw this and another thread that referenced this 'problem'. Sure enough, mine's off center too. Seeing as how mine has been 100% reliable for over 700 rounds, handles great, the sights are spot-on and has the perfect self defense trigger (lighter then the Sigma but not too light, like I find my MP9c), I don't see any issue with the gun or how S&W handled the original poster's warranty service. I've field stripped and clean my SD9 after each range session and have re-looked at all the parted just now, and don't see any unusual wear and tear on the frame where it touches the slide or any other adverse effects. If it is a defect, it appears to just be cosmetic. Treat the gun for what it is, a reasonably priced self defense weapon. Bottom line, as long as it functions/performs as expected, don't let a minor visual anomaly taint your use and enjoyment of the gun or sour you towards S&W's Customer Service.

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Cheers....Obi-GUN