Gentlemen, and ladies,; Went to a training class last weekend and ran into a new problem with my Glock 30. Actually the fist problem it has ever had of any kind. Seven rounds out of 350 fired struck the primer but failed to discharge the round. Strike was slightly off center but not much. Bought the gun used but have had it for several years with no problems at all. My guess is that it would have had about 3000 rounds through it. Took it apart, removed striker, it was a little dirty, cleaned it, put it back dry. It sounds like the striker is moving freely. Did not seem to make a difference. replaced the striker spring, did not seem to make a difference. with hindsight i am wondering if it was failing to go completely into battery. i did not think to check the problem while on the range, simply tapped, racked and went on. Did not attempt to refire any of the rounds but i think they will fire. Modifications to the gun are new sights, extended slide release, extended mag release and extended take down lever. all of them since my previous big range day. The only one of those i can imagine causing a problem might be the extended slide release. any insight would be appreciated.