Hi there! After watching this vid [ame="http://www.youtube.com/watch?v=7Fr5ccyriJI"]vid [/ame] that shows just how much polymer frame of Glock flexes, I started to wonder how attaching lights might impact gun reliability and performance. I've asked our local gunsmith, and he said that, yes, lights attached to Glock polymer frames can sometimes result in failure to eject or even double feeds. The metal clamps of my TLR-1 very firmly grab my g29 frame, which without a doubt reduces frame flexing. I wonder what's everyone's experience has been with this? Do you notice any weird behavior in your Glocks when attaching lights to it? Does Glock Co. test their guns with lights attached as extensively as guns without any attachments? Wanna kill these ads? We can help!