*
On the positive side, the Glock is reliable, durable, simple and inexpensive to manufacture. (Why isn't it inexpensive to buy?) It is simple to learn to operate by the new shooter, and therefore inexpensive to train new shooters (like new cops and infantrymen) to attain basic competence.
On the other hand;
1. Grip size. The grip of my Glock 20 is far bulkier than any other pistol I own. Since I have long fingers this is not a major problem, but it's getting there.
2. Balance. With a heavy slide and light grip frame, this thing balances like a brick with a plastic handle.
3. Ergonomics. The magazine release is not too bad, but the slide release is not easy to operate well. It should be. The take-down plunger is considerably more difficult to manage than need be. A lot of people have trouble with the grip angle.
4. No manual safety. The Glock is quite safe until you get a finger (maybe someone else's finger) or some sort of foreign object into the trigger guard. There was a small furor about this when a line of Fobus holsters had to be recalled after a retention strap got into the trigger guard of a Glock and caused an accidental discharge. Other similar incidents have happened. The Glock really ought to have a manual safety. I'm springing for one for mine.
5. Sharp-edged chamber throat. This means you're not supposed to shoot lead bullets. I think the lead bullet prohibition has little to do with polygonal rifling. I shot a lot of lead bullets through my stock Glock barrel without any detectable bore leading with normal cleaning. However, lead did accumulate at the leading edge of the chamber throat. If you shoot a lot of lead bullets (or even a whole lot of jacketed bullets) without frequent enough cleaning, this can cause the cartridges to fail to seat fully into the chamber. When this little problem combines with the next two design faults, then you may have a big problem.
6. Unsupported chamber. In order to promote better cartridge feeding, the chamber mouth has a rather large bevel, quite a bit larger than most other pistols. This, in turn, leaves the area of the cartridge near the case head with a considerable lack of support. If the chamber pressure is too high (this is not rare with some cartridges, like .40 S&W, even with nearly new factory ammo), or if the cartridge case is weaker than it should be (Don't shoot reloads with a stock Glock Barrel!), then you may have a problem. (Kaboom) This problem can combine with #5 to result in a larger problem (KABOOM). If you shoot reloads, especially with lead bullets, and you are less than 100% meticulous, then you can, without knowing it, achieve some undesirable combination of; leading in the chamber throat causing failure of the cartridge to seat fully, inadequately resized/poorly crimped cases causing failure of the cartridge to seat fully, slightly to extremely "hot" loads causing chamber pressure to exceed standards, overused brass becoming brittle causing weakness in the case head area, repeated resizing causing thinning of brass in the case head area, etc. Any and all of these factors can combine to really ruin your day. I don't think that there are any pistols that are completely immune to this sort of problem, but the Glock has a heaping helping of extra vulnerability.
7. Ability to fire out of battery. This means that the pistol can fire when the action is not completely closed and locked, as when the cartridge is too long or not fully chambered. It means that the pistol can fire when the thinner, weaker portion of the case is exposed in the overly large bevel of the chamber mouth. (Kaboom) This fault, combined with some of the previously mentioned faults, can give you a major problem (KABOOM) and possibly cost you an eye or a finger. In stock condition, my Glock could fire as much as .025" out of battery. In consideration of some of the foregoing points, I replaced the stock barrel with a "semi-drop in" barrel from Bar-Sto. It took about three good strokes from a medium India stone to fit the barrel, and then the pistol would not fire more than .0005" out of battery. Accuracy improved, too.
8. Relentlessly, devoutly crappy trigger. I have about thirty handguns, revolvers and autos, expensive and cheap; S&W, Colt, Ruger, Springfield Armory, Hi-Standard, Auto-Ord, Taurus, Rossi, Star. The Glock's trigger is nastier by far than any of them. It's not just that the trigger pull is long and heavy; most double-action revolvers have triggers that are considerably longer and heavier. But they can usually be made very smooth. The main trouble is that the Glock's trigger is very, very creepy; full of hesitations, false starts and false stops. In dealing with my Glock's trigger, I read books and fluffed and buffed, watched videos and buffed and fluffed, changed springs and connectors, etc. I finally bought a "3 1/2 pound trigger kit" (came out more like 4 pounds) and achieved some significant results. Instead of feeling like pulling a tomcat off a screen door, it now felt more like pulling a kitten off a screen door. In other words, the length of pull was reduced slightly, the weight was reduced considerably, and the creep was reduced hardly at all. Then I checked the lock-up. It now would fire .040" (!) out of battery. (Sigh)
The upshot is that the Glock is a simple and durable shooting device that could stand some improvement. It is not a fine firearm, not even close. Overpriced Tupperware.
*