Percieved problem: When a round is chambered in my S9, the slide will not self-return to battery when bumped (pushed back a bit). In other words, the slide will stick out of battery when bumped, and I will need to manually push it forward. SN on slide: greater than 20,000. Purchased: CDNN Testing Details on my new S9: 1) At the range: approx 500 rounds total through new S9. Two instances where I pulled the trigger without realizing that slide was not fully home (both were between shots of the same loaded clip). Dent in primer on both occasions, thankfully not enough for KB (kaboom). Both problems occured after 250 rounds (reasonable break-in). S9 was well-cleaned and oiled on all occasions. 2) At home: Round chambered; clip inserted with 1 additional round: Push the slide back 1/4 inch. Slide will not return home in any case unless you push it forward (or flip your wrist to shake it forward). 3) Ride the slide tests: There is some hangup on chambering (not too bad), but lockup home to battery is very weak. The top round in the clip gets grooves scraped into the brass from the slide. Small brass shavings present under slide. Percieved cause of problem: The clip spring pushes the top round upward against the slide. The slide rides on the top round using 2 sharp rails (on the underside of the slide). These slide-to-bullet "rails" bite into the brass, creating excess friction, and leaving brass shavings. Has anyone noticed the same?