So i took my CZ apart because I was going to start installing some new sights and just kinda polish the rails with 1500 grit sandpaper just to smooth it out a bit. When I did I noticed this blemish on the center rail on the slide that the hammer rides on. It does not appear to be an indentation but rather a line. It is where the hammer sits when the slide reaches it most rearward movement. This is not pic. I found it on the web but the mark looks similar. The other CZs I have dont have this mark but they also don't have the same round count. I am assuming this is normal but just wanted to ask. Thanks.

http://photobucket.com/gallery/user/70CamGuy/media/cGF0aDpDWi9EU0NfMTEyNC5qcGc=/?ref=

I'd say normal, and nothing to worry about.

It's probably caused by the hammer "bouncing" when the slide reaches the most rearward point, or also when the slide locks open on empty.  Since the hammer still has a little spring to it as the slide ides over it, those sunne stopping points for the mass of the slide jolts the hammer and as a result it gives that surface a small tap every time in that same spot.

Alright thanks. Like I said the CZs I have that I can compare it to only have a few 100 rounds each down them. The one I have that is showing that mark has about 4000 down it. Thanks

I don't see anything concerning there.