I saw the original copper lube when the gun was new. This is definately the outter layer of plating that is comming off exposing the apparently copper plating under layer,similar to a chrome plating prosess,of the steel rail. It catches a finger nail or a tool. So Reedo,does it eventually smooth itself out without gouging the slide? I have never seen this happen with a gen3 (this is my only gen4) and also there is no wear on the front rails.
Edit: checked out glocktalk,its common and possibly coated for corrosion resistance and like you said Reedo,works itself out with use. Thanks.
sent from my ATARI sc1224
Last edited by HiHoBrian; 01-13-2013 at 10:22 PM.