I bought my M&P 9 about two months ago and it has preformed flawlessly. My groups have all been a little left of Point of Aim, so I decided to move the rear sight just a bit to compensate. I removed the locking screw on the rear sight and started tapping the sight with a brass punch and hammer. Tapping didn't work and soon I was almost pounding the sight with the hammer...it won't budge. So my question to all you M&P experts is how do I get the rear sight to "Drift" without destroying it or the slide??