It is easy to go overboard on Glocks. They are so simple to take apart and work with, and the aftermarket so large and available, you sometimes have to resist the urge to toy with things, to fix what isn't broken.
I have a Glock 20 Gen III that I purchased back in 2005, when Doubletap Ammunition was still making its way through the forums and getting rave reviews. Mike McNett had sparked new life into the 10mm Auto and possibly started a revival. At the very least he proved that there was a market for full power 10mm, and that the 10mm was not dead. I purchased the Glock more out of curiosity about the 10mm Auto than a desire to own a Glock. The Glock 20 was one of the only available pistols in the cartridge at the time that didn't have a reputation for battering itself apart with full power ammo. The fact it also had almost double the competition's capacity at half the competition's price made it an easy choice. I quickly grew to love the Glock's simplicity. I purchased a decent amount of Doubletap's 180 gr Gold Dot load for defense but elected to reload practice ammo. I quickly discovered bulged cases and short case life were real issues with the slightly sloppy Glock chamber, more so than the over-hyped case support issues. I purchased a KKM Precision drop in barrel to preserve case life, and shortly after a stainless captive guide rod assembly with a 20 pound ISMI recoil spring to keep brass in the same area code. The stock 17 pound spring launched brass into low orbit. I tried a 22 pound spring on that guide rod and found that while the recoil impulse was smooth and the brass stayed noticeably closer, it increased recoil too much and could make it difficult to work slide with cold/numb and wet hands. So I settled on the 20 pound spring as being a happy medium. I eventually got along to replacing notoriously crappy plastic Glock sights with decent night sights. I settled on TrueGlo TFO and found them to be fantastic. I also picked up a $10 plastic aftermarket beavertail, which took mere seconds to install and has really saved my hands from slide bite, which can be another issue if you find yourself riding up on the Glock to control the sometimes snappy full power 10mm Auto. Around this time I installed an extended slide catch and manually filed down the magazine release. I was having trouble manipulating the slide catch with cold or gloved hands, and was having inadvertent magazine drops with gloves on (I shoot lefty because I am left-eye dominant). Finally, a member of THR,
TomJ, sent me a Phantom trigger kit for it not too long ago. I never had the complaints with the Glock factory trigger that some people do and by that time had enough rounds through mine that what roughness there was from factory had long since worn away, but you can't beat free. I again appreciated the Glock's simplicity as I once again installed something aftermarket by myself, without tools, in minutes, on four square feet of kitchen counter.
That leaves not much original on the old girl. Several years ago my truck was broken into while I was in the process of moving, and four guns along with half of my worldly possessions stolen. Since then, the Glock 20 has been my shadow and my rock, and my only handgun. In that role, it has excelled, though accepting those responsibilities with a heavy heart over the loss of its smaller and younger sibling, a Glock 19 I had purchased among the guns that was stolen.
And here is the heart of the issue in this long-winded post; the Glock 19 I had elected to keep 100% stock. I would have probably put better sights on it when I upgraded sights on the 10mm, but everything else would have stayed stock. Even with the Glock 20, the upgrades came over a period of a decade, with enough time to verify proper function. I knew the components work, or to what degree they affect function. I know the tighter chamber on the KKM hangs up a little bit more, especially with flatter nose profiles, but the improved polish seems to minimize this to the point it is worth it if you want to use your brass again, for example. And I kept factory parts, so I can return it to factory original condition. So I was never at any point chasing around issues because only one thing was ever changed at any given point. This is known as a control, in scientific terms.
Buying these heavily modified "race guns" for exorbitant sums of cash and then having to chase issues around or limit yourself to a specific type of ammo was how the 1911 earned a reputation as being unreliable. It is how you take a good gun with a stellar combat reputation and turn it into a choke artist. You'll note that everyone here knows Glocks by reputation run pretty reliable from the box, so their immediate recommendation is to simply restore it to factory condition, and then replace one part at a time until you identify problem? If that isn't a possibility, then you should send it back to whoever ruined it for you and get your money's worth out of it by making them chase the problem around until it functions correctly.
