OP, not trying to be rude or a smart ars, but after looking at your pic several times..... are you sure the finish is coming off, or could this be transfer or fouling?
and if it is the finish coming off, I agree with Austin1776.... although I'm sure HK CS would likely take care of you if you chose to go that route...
I purchased the gun from Gander Mtn., only got gun and one magazine. I have no way off knowing who the PO was.Strange. I haven't seen that before. As stated just a cosmetic issue but if the coating is in fact coming off I would probably check with hk. Or find out what the previous owner cleaned it with.
It's the bluing wearing off. I would purchase a bluing pen and run a few passes over it, wait a few seconds, then wipe it off.
There you go! If the pistol is holstered, shot, or handled the Bluing on the sights will wear through again sooner or later.I have been amazed by HK customer service, i sent an email explaining my problem and got a reply almost immediately requesting information for them to send me a shipping label to send my slide to have the sights replaced
Does this go on thicker than the pen?I find this works best for sight touch-ups and have used it countless times, especially on HK, Meprolight, and Trijicon sights. It works better than the bluing pen but you have to use a Q-tip to put it on so it's not as convenient as the bluing pen.