I own a 229ST and a regular 229. Tonight while cleaning the 229ST I noticed that inside the slide was a small area that was deforming/peening over. It is the part of the slide that comes in contact with the hammer as the slider cycles back. It is a little below that fireing pin where is starts to round under if you know what I mean. That part is getting slightly flattend and peening a bit. My regular 229 that has twice as many rounds through it does not have this at all.

Is this a problem? Thank you!

Doesn’t sound right to me.

I have a P229R with a blackened slide with maybe 1000 rounds through it.

There is a definite bright line caused by friction where the slide pushes the hammer back during recoil.  This bright line is maybe 2 MM wide and has a front to back curve to it (rather than any flats).

There is no indication whatsoever of any peening.

FWIW

Quoted: Doesn’t sound right to me. I have a P229R with a blackened slide with maybe 1000 rounds through it. There is a definite bright line caused by friction where the slide pushes the hammer back during recoil.  This bright line is maybe 2 MM wide and has a front to back curve to it (rather than any flats). There is no indication whatsoever of any peening. FWIW

My regular 229 is just as you describe.