My new (50 total rounds shot max) Range Officer in 9mm has an intermittent problem with the slide not locking back after the last round. It does this with both OEM magazines included in the SA Range Officer box. I looked at the problem closer and found that if the magazine follower is very slightly pushed to the rear of the magazine about 1mm-2mm or so the front of the follower lifts up slightly. In this position the follower does not engage the slide stop and even rides over the slide stop. When the magazine follower is completely forward in the magazine, it always properly engages the slide stop. Manually when cycling the slide it always engages properly, but when shooting ammo the magazine follower intermittently can slightly move back and not engage the slide stop on the last round. I called SA customer service and they said they will send out a replacement slide stop. Maybe it is slightly out of tolerance. It is a MIM part. Has anyone else on XD Talk seen this problem with a SA Range Officer in 9mm or .45 ACP? I don't have another brand of 1911 9mm magazine to try yet.