What type of jam is it, and what may cause it, when the spent rd gets stuck between the top of the slide and the next rd as the slide moves back from firing spent rd. I don't think this is a stove pipe, because the spent rd that is jammed is horizontal, (I wish I had taken a picture). I have about 280 rds through my NIB gen 4 26 purchased 10/31/12. I have only shot Winchester 115 gr 9mm luger 100 ct box from WM. I had the first jam at about the 125th rd and the second today at about 240 ct. Both jams accured when I was using the mag I installed the Pierce 39 extender on. After the jam today I shot another 40 rds with the same mag and, no problems.