As long as GLOCKs are fed FACTORY NEW AMMO, you will never have a problem!
I blew up my G35 about three weeks ago. I had a match STORMLAKE barrel on it and they have a very tight chamber. I was using my reloads, casted bullets over not alot of BLUEDOT seated short. But the slide stop had taken a beating and it broke, causing my silde to fly off. My GLOCK certified armorer looked it over and repaired it, I still had the original barrel to put back o it, and I traded it off two counties over!
Was it my fault? I guess. I shoot the same load through my older XD40 TACTICAL and never had a problem. ALso, this load was the only load that went through a buddies Ruger 40cal and my HiPoint 40JCP.
I still carry a GLOCK as my duty weapon (G22, AUX LEO), but I don't own anymore. If it can't eat cast bullets, then I can't afford it fed it.
I don't drink the "GLOCK Perfection" kool-aid, but I believe that it is a great handgun in certain calibers. I don't think there is a better full size 9mm than than the G17. All other models seem to have a problem, but that's just internet chat. I personally only seen two GLOCKs KB, mine and another LEO who was using relaoded ammo in his 40S&W. But alot of what is said about GLOCKs, good and bad, can be said about alot of newer designed handguns.
Lefty