Hey all, I have been lurking for a while reading tons of useful information on this forum and wanted to thank everyone for all the great threads/posts. I have had a Glock 17 Gen 1 since new in 1988. I have recently gotten back into going to the range and shooting etc. Because of this, I decided to send my Glock 17 into the factory to have all the parts upgraded. The gun was working fine, and has maybe had 2000-3000 rounds put through it since I have owned it-it is in perfect shape with no damage or anything like that. However, upon conversing with Glock technical services, they indicated that it was good idea to replace all the parts with the upgrade parts that they have been doing since 1992. They sent it back like a brand new gun, having replaced mostly all of the internal parts (15 total). So . . . my question is: Since I have gotten it back, when i took it to the range, I noticed it doing something it never did before. After I empty a mag, and the slide is in the locked/open position, when I insert a new loaded mag, the slide automatically releases. If I put the new mag in very gently, this does not happen. However, if I shove it in with normal pressure, most of the time the slide releases without having to hit the thumb release. They did replace the thumb release (part 406-2). I have been told by a guy at a local gun store that maybe the spring is stronger on the new slide release catch, and when you insert a mag with some force, the spring is more prone to being jolted and snapping down the the thumb release, allowing the slide to go forward. Is this normal? The gun definitely did not do this before parts were replaced. I have a new Gen 3 Glock 17 as well, that I recently purchased and it does not do this. Please let me know if anyone knows of a solution to this issue. Thanks! Jason.