Long time Glock owner, brand new Glock Talker. Bought my first Glock around 2007. It was the 27 with frying pan finish. Shortly after, I acquired a Gen 3 17, Gen 3 26, and now most recently a Vickers Tactical 17 I bought used. Regarding my 27, today I noticed an indentation inside the top of the slide. It's just forward of the cutout for the barrel hood. Shot relatively little over the years but it has been my primary carry since new. Always factory ammo. Never +P with defensive loads. I literally fired one round of Federal HST 180 gr today. Field stripped to swab the barrel and noticed the indentation. I might be crazy but I don't remember this being there. And there are no marks on the barrel that I can see. What do you guys think? Thank you in advance!!!