Originally Posted by voyager4520
My Gen3 G27 that ejected erratically showed the same wear to the EDP. Every case of erratic ejection I've seen in which the EDP was examined, though few, showed the same wear. I wonder if the EDP channel may be too tight.
My suspicion at the time was that part of the EDP is slightly tapered and gets wider toward the muzzle end. In my G27 the gap between the extractor claw and breech face is noticeably bigger than in my G23, even when the extractors are swapped between the two. That suggests to me that the extractor indeed sits further forward in the slide, allowing the EDP to protrude slightly more from its channel with the slightly smaller diameter portion rubbing against the opening of that channel. There's a similar wear mark on the EDP of my G23 but it's ever so slightly further forward and it's no where near as pronounced.
As I have said before, based on my gun at least, too tight isn't the problem. There enough room in the EDP channel for the EDP to wiggle a little, so it's not binding. My guess is that the front end of the channel is very hard and very sharp.
You have said something very interesting that hasn't been mentioned before. That is that there is a different amount of space between the extractor claw and the breech face with different slides and the same extractor. Different models I realize, so not apples to apples. Still, I wonder if this doesn't lend some credibility to those who are saying that some of the slides are out of spec. It would be interesting to get a few owners of the same model and generation together and try this.