I tried a KT finger extension (P3AT-309 grip extension) for the first time today and after shooting three magazines, the extension just fell away from the mag as I went to reload - the plastic grooves on the extension had broken off. Fortunately the spring didn't go flying off and I happened to have another grip extension that I purchased for a second magazine. I installed it and shot four more magazines before quitting for the day. I looked at the second grip extension and saw that a crack had formed along the outside of one of the plastic grooves. Obviously it was on its way to failing like the first one. Anyone have a similar problem? I did a search and found that people have had problems with mag dropping during shooting when it has an extension, but I didn't see any reports about the extensions actually breaking. Other than this, the gun has been trouble free since purchase, with probably about 400 rounds through it.