Originally Posted By LampShadeActual
Not wear. The added metal hanging on the end of the barrel is causing a torque effect so that the left rear corner of the barrel is being banged upward into the underneath rear of the slide. It is not forward and back wear, but a hammering effect. Look at the slide. It is a simple chewed dent.
The alternative is that the frame and barrel locations system is flexing enough to do the same thing however you would wish to describe it.
Pot metal/soft aluminum slide material isn't steel. Clearly the sharp barrel corner rotated around the long axis of the barrel up into the slide.
Visualizing the parts and function, this would be when the slide is all the way to the rear and the barrel assembly is the least supported. That's why the damage is forward of the ejection port.
Yeah I figured it was impacting or rubbing based on the location. It strikes me as odd since a lot of people use these with suppressors. I could find no other instance of this type of wear online. I am hoping it will not progress much more than this. The lower/ frame is all very tight and no movement so hopefully it just some tolerances working themselves out. It runs great. I don't care how it looks under there but if it starts to affect function or gets a lot deeper, I will send it to S&W.