I had this happen to me Monday night. 3rd shot of the 2nd string, I heard a lighter than normal pop. Much louder than a squib, but no slide recoil, and I felt a face full of unburned powder. I stopped myself, and ran the slide to show clear, and noticed brass in the chamber that wouldn't come out. I then noticed the extractor missing from the slide. I locked the slide back manually, and cleared the brass in the safety area with a punch. A buddy found the extractor, intact, on the floor. The brass was headstamped "Perfecta" which I recall seeing in Walmarts a couple years ago. I pulled the slide plate off and reassembled the extractor, went out to the plate rack and cleaned the rack 5-6 times, no problems. I shot the stage over again, and it was fine. The brass had a ring bulge all the way around, and a blow out at 6 o'clock. All my other brass before and after it were fine and normal. The gun was a Legion lower with my X5 upper, 11.5# recoil spring on a Springer steel guide rod.