I imagine, if I should enlarge a 10 Megapixel image of any "particular-spot" inside any of my guns or on the edges of visible outer-surfaces, I would find the same kind of things that could be taken as some kind of flaw in any of the quality firearms I own, regardless of whether the subject surface is aluminum, steel, iron, brass, copper, titanium, some kind of polymer, or any other material!
My take on this is that one needs to look at the area (in general) and determine if this particular area which contains such an anomaly is, or is not a critical area with respect to how the gun operates and functions, as a complete unit, and whether said anomaly detracts from the function, usability and/or safety of the firearm in general.
If it is determined upon above-mentioned scrutiny that the subject area is, in fact, a fundamental surface with respect to the function of the weapon and/or any of its component parts, then the weapon should not be fired again until the manufacturer has eliminated any such problem or (the manufacturer) has stated, in writing, that any such anomaly is normal for that particular area and merely represents typical manufacturing techniques and does not, in any way, detract from any function and/or safety in any way shape or form!
I had a similar problem and I emailed the photos showing the precise location and zoomed in on what I questioned was an issue with a pistol and the manufacturer emailed me back stating it was not normal and a new slide was in the mail that day, included was a tyvek envelope to return the defective assembly back to the manufacturer. This was after owning the gun for over two years.
You need to be sure you reach a technician, i.e., someone who is familiar with the manufacture-process of the weapon and all phases of manufacture.
