When I bought my Glock 17 in 1992, it came with two 17-round magazines. I soon discovered that Glock made "plus 2" extenders that pushed the capacity to 19 rounds, plus one in the chamber giving me twenty rounds total. At the same time I bought the "plus 2's" I also bought an extra magazine, so I could have two spares for defense or competition.
If you know anything about Glock magazines, these magazines were the Non Fully Metal Lined (NFML) magazines, essentially polymer bodies with a metal liner that didn't go all the way around the inside if the magazine. Because of this, these magazines swell when they are loaded, hence their alternate name, "Non Drop Free" - when loaded, they don't drop out of the gun under gravity when you press the magazine release.
There are obvious problems with this design. One, tactical reloads are problematic because you have to pull the magazine out. IDPA rules notwithstanding, if I want a magazine out of my gun in a hurry, I'd like gravity to do the work. Plus, over time, loading and unloading NFML magazines flexes the polymer and the metal lining, leading to material fatigue. Remember that part.
Glock fixed these problems later with the Fully Metal Lined (FML) mags, but they don't swap old mags for new. (I know because I asked, nicely, just this week.) So I bought three FML magazines and three "Plus 2's" for those, giving me six mags total.
Alas, nothing lasts forever.
When I was at the range last month with the Dauphin and his friends, I had a failure to feed using Magazine 2. I did the Tap-Rack drill, and still nothing. So I dropped the magazine (actually, I pulled the magazine out, since that's what you have to do with NFML magazines) and I saw that a couple of the rounds, about midway down the magazine, had caused the mag to swell to the point where they weren't in a nice straight staggered column any more. They were wedged in there so that the mag spring would not push the rounds up. Once I saw that, I banged the mag on a shooting bench, and the rounds loosened up and the mag worked again.
Then, last weekend at the Blogger Shoot, the same thing happened again. Since I numbered my magazines a couple of years ago, I knew this was the same mag that had given me problems before. Banging on the mag worked again, but I decided right then that Magazine Two was history.
I will keep it around, for reloading practice, but I plan to replace it with a FML magazine in the near future. As for the other two NFML magazines I still have, they haven't given me any problems yet. But I will keep an eye on them, and I won't use them for defense or competition. Yes, I could replace the mag springs with new ones, and that might fix the problem, for a while. But I think I'm still taking a risk with these mags, which means I need to get a few more FML mags to replace them.
Sounds like an excuse to head to the gun show this weekend, doesn't it?
