Hey, just wanted to thank you for answering my previous question awhile back, and for having such a well done website- I tend to drop by and read the latest entries every week or so, so well done! I have a quick question for you that I’m hoping you can answer for me, I know that peening on the slide rails is normal in a glock, but putting a couple hundred rounds through my new 23, I’m noticing a wear mark on the left side of the slide, right where the end of the barrel mates with the slide (basically opposite of the ejection port). I’m assuming it’s just growing pains and normal, but thought I would double check. Have a good one, and thanks!

Good to hear from you.  I just stripped my 23 that’s got about a million rounds and, yep, sure enough, there is a little polishing right opposite the ejection port.  Never noticed it before.  Remember, your slide is Parkerized.  That’s the black coating.  You are not wearing off the Tenifer treatment.  You will also start (if you haven’t already) noticing a polish on the ceiling of the slide from the barrel lug rubbing.  Don’t worry, it’s just working the way it’s supposed to.
Hope this helps,