of the finish on my 340 M&P. I have only been carrying it for about six months, on a daily basis, and it looks well worn. I carry it daily while working outside and there is noticeable wear on the muzzle, the top strap, and in front of the crane. I also have rust on the cylinder release latch as well as the left side of the trigger. I also blow it off with an air compressor and wipe it down at the end of each day with light oil as necessary. I carry the gun in a Desantis front pocket holster, which is very comfortable and easy to draw from.
Don't get me wrong, I liked the gun enough, after shooting it only once, that I went back and bought a second 340 M&P from the same gun shop a few days later. But in my experience, the finish is anything but durable. I am in N.C. and carried a Glock on-duty for years with nowhere near the same finish wear. YMMV