Some of the information presented on the suspected accuracy issues has been quite interesting.

Several months ago I picked up a M&P9 for a screaming deal at a local pawn shop (scared me that I could actually find a deal at this particular pawn show. In hindsight I'm starting to wonder if the screaming deal was offered for a reason?). Took it to the range and found that at 15 yards it was shooting a good 3-inches to the right of POA. Quadruple checked my grip, my stance, tried closing one eye, spent a couple hours with an instructor I know, etc. I probably tried every logical and illogical thing I could possible try to determine the cause. Tried alternating with another pistol but while the other pistol shot to POA, the M&P9 shot 3-inches to the right of POA.

I replaced the stock sights on the M&P which marginally improved things but I was still shooting to the right of POA. Out of curiousity and frustration, I ordered a replacement M&P9 barrel from Brownells. Not exactly what I wanted to be spending my limited savings on, but I needed to know what was going on. Installed the new barrel and went to the range. My M&P is now shooting at POA. Re-installed the old barrel in the M&P - 3-inches to the right of POA. Replaced the new barrel - shooting at POA.

While this experiment was by no means scientific and is certainly not conclusive, I suspect that I'm going to keep the new barrel in my M&P. In looking at the rifling of the old barrel I can't see anything out of the ordinary. That said I'm no gunsmith so I make no guarantees that I'd even know what to look for.