This may have some bearing. I posted this on another Glock forum website. "If you look at your recoil spring assembly on your 27, you will notice that it is bowed (not perfectly straight). If you place the bow of the spring facing downward toward the frame, you may experience problems with the field stripping. If you place the spring in any other way that is to say bow up or sideways you'll be fine. Before I figured this out I would occasionally have a hard time with field stripping. So much so that I gouged the inside of the frame of my 26. I noticed when cleaning my guns with a friend who also owns a 26, that his frame was gouged in much the same way. He didn't notice the gouges until I mentioned them. When the bow is toward the frame the rear contact point of the RSA is tilted back toward the slide lock bar so when you pull down on the slide lock you inadvertently pull the RSA from the barrel. I have muscled the slide off in this situation and caused the frame gouging. The better way is to push down on the front of the exposed RSA and re seat the rear portion onto the barrel." You are probably aware that their are some dimensional difference in the slides length between the two generations, according to Glock's website.