Hey, guys. I recently got a 9mm S&W M&P. I've shot about 400 rounds through it, and I took it home to clean it. I accidentally (or ignorantly), brushed some of the finish off with a bore brush where the firing pin comes out to strike the primer. Is this going to cause a problem? What should I do? Just keep it lightly lubricated? I know that it's generally a bad idea to put oil near the firing pin, because of the dust, etc. that it collects. Thanks in advance.

I suspect that instead of removing any finish, the finish removed some of the brass from the brush. That Melonite is tough.

Try wiping the spot off with a good copper solvent.

That's the Breech Face. I do believe that area is Melonited to start with but trust me, it will wear from normal use and cleaning. Just clean and oil it as normal. It's always a good idea to wipe any gun down with a light coating of oil...I even do that with my Stainless guns...including my M&P. Did you know the M&P slide is stainless under the Melonite?

That area is stainless, and should not pose any problem. Even though it is not coated from the factory. You just cleaned it well enough to remove the carbon residue off the pistol in that area, which is kinda hard to clean anyways.