Took my new M&P-9 (Serial # DTC96**) with ambidextrous safety shooting for the first time yesterday.

Within the first 100-rounds my groupings started to go right from point-of-aim. I could literally see my front-sight post progressively sliding to left in the slide's dovetail.

Shortly thereafter the front sight was way left. After clearing my M&P, I braced the slide against the wooden bench and tapped the slide with my hand, the sight went all the way to the right, turning the slide around I tapped to get the sight centered but it slid right out of the dovetail to the left and out onto the floor. Hmmmmmm...

Figuring this could just be an issue with the sight, having a set of new factory night-sights on hand which I planned on installing when I can afford the sight pusher (along with the Apex duty package), I tried the Trijicon marked sight and could slide the front sight in almost fully using only two fingers. I then braced the slide and sight against the bench and tapped the slide by hand to center the front sight post. Needless to say, I could shoot tight groupings all day long with the M&P, provided the sight wasn't drifting out on me and it is a real pleasure to shoot - I love the gun, but this issue is of course a concern as far as QC is concerned.

I now have two useless front-sight posts (factory white dot and tritium). I think as the slide warmed up from the shooting (just over 300-rounds total - for the day - of Lawman 115gr FMJ, but issues showing under the first 100-rounds) the dovetail was opening and the recoil assisted the sight in drifting. Both front-sight posts appear to be consistent in their sizing, so the dovetail may be too large.

Has anyone else experienced this issue?

I am waiting to hear back from S&W Customer Service to resolve the issue, needless to say it was disappointing to experience and see the issue... but alas, rather on the range than in a gunfight.

She shoots better than my GLOCK22 and I plan on purchasing both an M&P-40 and M&P-45 Mid-Size I like it that much, but have never ever had an issue crop up like this one from any other manufacturer.

My sister-in-law giving her a go on the range yesterday :