That wouldn't surprise me - you're probably right, i may have scraped the chrome plate off. The chroming was not exactly top notch i don't think, I can't remember seeing chrome plating that wasn't SHINY.
I also have a titanium plated cam pin, i should have taken a picture of that too; the plating was totally gone, worn off from the part of the cam pin where it wears in the classic swirl pattern, after 100 rounds.
I have thought of getting the "Fail zero" parts but they are very pricey for the problem they are supposed to solve. Honestly if I had known how dirty the DI AR's get, and what a PITA to properly clean (dirty guns
really bug me - yes, I have some kind of weird OCD, my apartments a mess but all my guns are spotless...)
Not to turn this into a piston gun post but allow me to stray a bit off topic for a minute....i wish i had bought the Stag 8 piston AR, it was less then $200 more at the same gun store. No worries about scraping bolts or carriers, just the piston. Some pics...i wonder how much they'd sell a conversion kit probably a lot...
Gas block on Model 8
http://i80.photobucket.com/albums/j1...AG-PISTON2.jpg
Piston rod and spring and gas plug
http://i80.photobucket.com/albums/j1...TAGPISTON3.jpg
Piston and rod replaces gas tube
http://i80.photobucket.com/albums/j1...AG_PISTON1.jpg
The bolt carrier...Stag claims the design eliminates bolt tilt.
http://i80.photobucket.com/albums/j1...PISTONBOLT.jpg