I have a third generation Glock 23 which has had an ongoing failure to feed (FTF) problem. This was my first pistol, and at this point may be my last Glock. In training classes, the instructors told me I must be limp-wristing it, so I kept working to correct my grip. The cartridge hangs up at an angle on the feed ramp. Jarring the pistol causes the feed to complete. There seems to be no connection to how full the magazine is. The problem happens with every ammo brand I tried including: Remington UMC 40 S&W 180 gr (10% FTF) Winchester white box 40 S&W 165gr (5% FTF) Hornady 40S&W Critical Defense 165gr FTX (5% FTF) Ive tried 5 different magazines: 3 new 10-round, 2 pre-ban 13-round (Im in New York). All magazines have #1 followers and 9-coil springs. I gave a box of the Remington ammo to a friend who has the identical pistol and he had no problems. Following my first conversation with Glock I received three 10-coil springs and three #5 followers. (It took a month to receive the replacement parts.) The #5 followers would not fit in the magazine, they scrape on the sides. But I tried one of the springs. No change in results. I sent the pistol to Glock for repair. Over a month later I received it as repaired with no changes I could recognize and no description of what was done. My first shot with the repaired pistol resulted in an FTF. In all, I got a 25% FTF rate. It seemed worse. I asked the owner of our local firearms school to try my gun. He experienced the same failure rate. (He shoots Glock.) I sent the pistol back to Glock. Over another month later I received the repaired G23 with what appeared to be a replacement 10-round magazine and no description of what was done. At the range, my third shot with that magazine was FTF. I tried the Remington and Winchester ammo above. I tried all my 10-round magazines including the one just received from Glock, and also the one with a 10-coil spring (which Glock sent earlier). All combinations resulted in frequent FTF. This time I took the gun to the dealer from where I purchased it. He tested and was able to reproduce the problem. He is now talking to a Glock representative and Im waiting to hear back. My gunsmith tells me that he has seen a pattern of problems specifically with the G23. He has heard of this pattern from other gunsmiths also. Does anyone have any suggestions on how to get Glock to take care of this?