While working on my last column about general gun maintenance, it occurred to me that a lot of folks I talk to don't seem to know some of the simple, yet important points about how their Glocks work and how to anticipate or troubleshoot problems. I see a lot of them in classes, and Glock is claiming a 70+ percent share of the law enforcement market these days. With that in mind, here are a few things that might help you keep them running like...well, Glocks. I'm going to assume you can field-strip your gun correctly, so I'm not going into that specifically. And I'm not going to go into any further disassembly other than basic field stripping. If you discover by doing these checks that you have a potential problem, get the gun to your local Glock armorer.
Is it loaded?
First of all, since you have to pull the trigger to take a Glock apart, I better emphasize how important it is to make sure the pistol is empty before you begin. I'm still seeing periodic reports of people who didn't, with results from merely embarrassing to serious personal injury. For heaven's sake, triple check to make sure it is empty, and keep it pointed in a safe direction! Once you start the slide forward after releasing the slide lock, you may find that it binds up after moving only a fraction of an inch. This is particularly true if it has a New York-style trigger spring. That's normal. Just pull the trigger a second time and ease the slide off the frame. Once the slide is off the frame, hold it upside down and look at it from the side. You'll notice the back of the recoil spring/guide rod assembly is sitting up slightly from the half-moon shaped notch in the barrel lug, where you seated it when you last assembled it. What you are looking at is the normal operating position for that assembly. You want to make sure that you push it back down into the notch before reassembling the slide to the frame. If not, you can chip the edge of the rod and that will cause malfunctions. Most folks never notice this, because they usually take the slide components apart when they field strip the pistol. But if you ever remove the slide just to do something with the frame, you need to know about this before you put the slide back on.
What's that for?
While you have the slide in your hand, remove the recoil spring assembly and the barrel and hold the slide so it is muzzle end down and the bottom facing you. See the hole just the above the breech face? That's not a lubrication hole. It leads into the firing pin channel and is there to allow any debris in the channel to work its way out. If you put oil in there, it will literally gum up the works, as it holds in the stuff that would normally find its own way out. The firing pin assembly moves in its channel, inside a polymer liner. That provides all the "lubrication" needed. Make sure the firing pin is in its rearward position (sometimes it is protruding through the breech face when you take the gun apart). If you hold the slide vertically and push in on the firing pin safety (the round, spring loaded button), the firing pin should drop freely from its own weight into the "fired" position. If not, try holding the button in and move the firing pin gently up and down with your finger. If it is binding at all, the firing pin channel needs cleaning. (That's an armorer's job.) By the way, never push the firing pin to the rear against its own spring tension and allow it to snap forward. This can damage the firing pin safety, causing it to fail.
Another way to help keep junk out of the firing pin channel is to make sure you hold the slide "muzzle down" when you are cleaning the breech face and the extractor. If you hold it "muzzle up" (so it's easier to see what you are doing), dirt, solvents and lubricants can get into the channel through the hole in the breech face. Again, this is to be avoided. One last point on the slide operation: check to be sure the extractor isn't damaged. Look at it from the bottom, because it can look normal from the top, but the bottom edge, where most of the wear happens, can be chipped.
Moving on to the frame, be sure and check the pins. I've seen a number of broken pins, but the pistol was still functioning. The pins should be more or less flush on both sides. If not, a piece may have broken off and fallen out of the hole. Also, make sure the spring is okay under the slide lock. You can feel the tension when you pull down on the ends of the stop. When that spring breaks, the stop falls out to the side and the slide itself starts to head downrange. Also check the spring tension on the slide stop lever by gently lifting up on the lever (just enough to feel the tension). It can easily be damaged by improper assembly. If it is, the slide will usually keep locking back as the lever flips up during recoil. If it happens in the field, at least you can push it down and keep shooting. Visually check everything for cracks and/or wear. I've seen frame rails crack, but usually the gun keeps working. Take a close look during cleaning.
The most common problem I've seen (and it's not all that common), is a broken factory coil style trigger spring. I have heard of NY trigger springs breaking, but I've never actually seen one. The coil springs seem to be less durable. If the spring (it is actually the "trigger reset" spring) breaks, the trigger will remain in the rearward position when the slide cycles. If you're in the middle of a gunfight, that's a huge problem. So here is a gunfight survival tip for you: To keep the pistol running, hold the trigger to the rear and hand cycle the slide. Then release the pressure on the trigger and it will reset. You can keep firing that way, as long as you maintain rearward trigger pressure until after the slide has cycled. Actually, you might not even notice it in a gunfight, unless you let off on the trigger pretty quickly. But it may happen, and now you know how to keep it running.
Now, a few words about magazines. The most important words are: Don't lubricate the magazines. Like the firing pin channel, solvents or oil will only attract and hold dirt, causing feeding problems. You should disassemble the mags and clean them at least after each shooting session. Periodic cleaning, even if you have only carried them around for a while, is a good idea. The easiest way to remove the floor plate from the magazine is to use a 3/32" punch (the same size as the Glock armorers tool). Use the tool to push in the button on the floor plate and the insert will move off to the side (inside the magazine). Then use the tool, still in the hole, to carefully start levering the floor plate off. Be sure you "capture" the spring as the plate slides off. Then you can remove the spring and follower and clean the inside of the magazine tube with a clean, dry cloth or magazine swab. Wipe off the coils of the spring, too. If you have a new spring handy, check the used one against it. If it is more than two coils shorter than the new one, change the spring. Once you have it all clean and dry, it can be reassembled. A lot of malfunctions are magazine related. For example, if a cartridge feeds high and hangs up on the top of the chamber, the magazine lips may be too far apart. If the cartridge nose dives into the feed ramp, the lips are probably too close together. Change magazines and try again. Well maintained magazines can prevent all sorts of trouble.
Finally, a little about lubrication. Some folks have noted that people seem to over-lubricate their handguns and under-lubricate their long guns The only points on a Glock that need to be lubricated are the slide rails/frame rails, the outside of the barrel, the barrel hood or the corresponding wear point on the inside top of the slide, the barrel lug and, most importantly, the connector (that hook-like thing that sticks up next to the right rear frame rail). Just one drop only at each spot, please. Anything else is wasted.
With any luck, you've heard all of this before. But apparently a lot of folks haven't, so I hope it helps. None of it, of course, can replace the recommended annual inspection by a Glock certified armorer. If your agency is willing to sponsor you to attend the Glock armorers course, get in touch with them at the link below. It's money well spent.