The last time I went out to shoot my Glock 26, I noted with just a small amount of dismay that I was getting a misfire about every 10th to 20th round. I examined the pistol with a quick once over and saw nothing wrong, though I knew it was dirty -m very dirty. I am guessing I had fired about 750 or more (probably closer to a thousand) rounds through it, over the course of 2 or 3 range trips, without a cleaning. After taking a look at the Glock 26, I gathered up some of the spent shell casings and gave them the once over. Ah,there was the problem. The primers were being struck by the firing pin off center on the rounds that failed to fire. A closer look and it seemed the hits were also lighter than usual. Being the trained and certified Glock Armorer that I am, I immediately realized that the problem was probably caused by the pistol being as dirty as it was and more specifically that the locking lug was dirty thus preventing the pistol from going perfectly into battery but still enough to operate the trigger and firing pin.
Being that I was at the XXXXXXX County Rifle & Pistol Range, I could not clean it there, then try firing it again to see if that was the problem. They do not allow gun cleaning at the range though I am willing to bet there is someplace in there where it could be done safely. That really did not matter too much, as I recall, I was pretty much out of ammo anyway. So off to home I went and the Glock was cleaned up and put away. That was weeks ago. Last night I gave it another light cleaning in anticipation of going to the range for work today to qualify. I can happily say, the cleaning did the trick. The Glock went into battery perfectly for every shot of the qualification course, all shots fired. I did not check any of the shell casings to determine if they were still being struck off center but am pretty satisfied that the problem has been solved. next time I am at the indoor range I will check the shell casings, there just was not time today during the quals.
If you wind up ever having the same problem, I recommend that you field strip the Glock and do a thorough cleaning. Then take it for a test firing. If the problem has been solved after the cleaning, then things are probably well and good. If not, get it to an armorer for inspection. By the way, this is something that can happen with Glocks such as the Glock 17, 19, 26, 22, 23, 27 and so on. I do not recall if this applies to Glocks of the Gen 4 design or not.
All the best,
14 hours ago