That doesn't sound right. Call up HK and be honest about your carry routine, whether you store the weapon in the holster after carrying, and your maintenance schedule, and hopefully they'll give you a new slide. A nitrocarburized slide shouldn't rust. It's not a "maybe" or "if" or a conditional statement dependent upon you babying the slide. The only reason undamaged nitrocarburized steel will rust is if it's nitrocarbed improperly, ala early make S&W M&P's, or exposed to a hostile environment for extended periods.P2000 date code AF.
I have carried this gun for quite some time and it has a bit of slide finish wear. Which doesn't bother me in the least. I normally carry in a Crossbreed IWB or occasionally in a Raven Concealment or Aker OWB.
But for the last few days I have been trying out a Smartcarry holster. I am liking the Smartcarry and appendix carry in general.
I was sitting home today and decided to strip down my P2000 and clean it out. It's my edc and I thought I would clean it up and relube it. While breaking it down I thought the proof marks and serial number looked odd. They are usually a little gold looking, today they looked orange. Upon closer inspection I could barely make out the proof marks. they were a solid blob of rust orange. I wish I had taken pictures but my first reaction was to grab some gun oil and a terry cloth and get to rubbing.
Most of it came off the serial numbers. It still has some on the proof marks.
Is this common? Now I'm debating getting it refinished in NP3 or CPII. Wear I don't mind, rust I can't handle.
Unless, of course, those numbers are stamped after the slide has been nitrocarb'd. Then it'd just be bare carbon steel protected by the black oxide finish (read: industrial, utilitarian bluing). If that's the case, I wouldn't be surprised if rust were to develop when exposed to sweat or whatnot....but I think everything done to the slide is done before the nitrocarb process.