So I'm a Glock newb. Just purchased a used Glock 17 2nd gen. It has LE/GOVT restricted mags and so I'm told is or may be a retired police issue. Other than that I don't know much else. When I perform the procedure to remove the slide from the frame I begin to move the slide forward and I'm hearing a distinct clicking sound and notice a slight movement in the trigger along with the sound. At first I thought it is the trigger bar ramp that pushes down the firing pin safety making the sound and that it is due to getting hung up on it. However, when looking down the mag well I now think the guide rod and recoil spring are getting snagged on some part of the frame. I seat the guide rod every time I practice disassembly but it seems to always pop out of the recess onto the step above the recess on the barrel. So I think it's the spring getting snagged on the slide lock lever and the movement I saw was just the interaction of the trigger bar and the firing pin safety. This common? Uncommon? This going to be an issue? The spring and the rod look in good condition. Fix? Another issue is the ramp for the trigger bar. It appears worn. It doesn't seem to be non functional, but I wonder how long it will last. Should I replace it? Next thing would be appears to be a small sliver of metal missing from the ridge inside the slide around the chamber area. Hot load? Malfunction? Issues? Last thing is that I noticed that toward the end of the slide it appears that part of the slide is higher than the other. It looks like a result of manufacturing. Is that supposed to be there?