I will start this by saying I’m a lil OCD about reliability issues, and so other folks might have had different experiences.
I am very fond of both these guns and carry them regularly. I’ve got maybe 6,000 rounds through the G43 and 3,000 rounds through the G48. A substantial amount of that is with HST and Gold dots, not ball. I noticed early that both guns got a little bit hiccup-y with certain types of hollowpoints, especially shooting from compromised positions, one handed etc. Because I noticed this early on, I ended up putting several cases of carry ammo through both guns. These are the only ammo-sensitive Glocks I have ever owned. I’ve now put more money in HSTs and Gold Dots through these guns than I paid for the guns themselves.
Both guns are accurate and reliable but not the way a G17 or G19 is. They are extremely accurate, actually. With ammo they like, both guns will stack most of their magazine in the X ring at 25 yards, if I can do my part. They are definitely more accurate than some of my sloppier full size Glocks.
Reliability is another story. If you’ve also shot a few thousand rounds of HST’s and gold dots through your G43 or G48, I’m very happy to hear if your experience differs from mine. I would love to find out that in fact, I have simply bought two lemons. But I’m guessing most folks shoot mostly ball and maybe run a box of HSTs or Gold Dots and call it good. For the G43 or 48 that might not be enough. In fact, I can say pretty confidently that it is not enough.
What I found is that the G43 runs very well with the stock 6 round magazines. If you stick with those magazines, you’re good. But the instant you put an extended base plate on, you’re messing with a very tightly calibrated system with a much narrower window of function than a G17 has.
Again, ball is not an issue—all of my issues revolved around feeding HSTs and Gold dots of various weights (115, 124, 147). At any rate, the G43 needs a very strong magazine spring. The Zev extra power springs are basically a requirement if you run an extended baseplate, or eventually you’ll end up with feeding issues.
Note—I have like ten magazines for each of these guns. I numbered them and began keeping careful notes when all this shit started happening. I was praying for this to be a magazine issue. It isn’t.
Other than needing a lot more magazine spring tension than the full sized Glocks, another weak spot is the recoil spring. It really does not last very long. I went through them every five hundred rounds, or sometimes half that if I was shooting hot ammo.
Another thing both guns are picky about is slide velocity. Under adverse conditions (weak hand shooting, slightly weak mag spring, slightly weak recoil spring), neither gun runs well with heavier ammo, especially everyone’s favorite (and mine), 147 HST. I would be very careful about running this stuff in those guns, especially if the recoil spring has some mileage and you’re running an extended baseplate. I got regular failures to return to battery when everything wasn’t perfect.
I think that while the 147’s generate a strong recoil impulse, they are not as snappy as 124’s and 115 grain loads. With the 147’s, once you get some miles on both of these guns, you can often feel the slide sluggishly popping that final 1/8” into battery. This is with 147 HSTs and 147 HST +P’s—I noticed no difference between the two.
124’s were better, but still not perfect. In my G43, at least with an extended baseplate and some miles on the recoil spring, the only round I found that functioned with total reliability is the 115 gold dot. It just runs the slide quicker—returns to battery every time. With any other ammo than 115 Gold dot, as soon as the mag spring gets weak or the recoil spring gets weak, you can easily induce a failure to feed or failure to return to battery, by shooting with a slightly compromised grip. The 115 Gold Dots I simply could not get to jam.
Note that in an effort to address these issues, I polished the shit out of the feed ramp and every single other friction inducing part on the gun. My G43 is probably the smoothest one on earth. Definitely the smoothest Glock I own. Maybe the polishing helped, I dunno.
The G48 shares some of the same issues, mostly in that it uses the same marginal recoil spring assembly. The factory mag springs are very strong and probably no one’s putting a baseplate on.
The 147 HST’s definitely ran in the G48 when the gun was brand new—in fact they ran so well that I put a taller front sight on to get the POI set for them. But as soon as the recoil spring got some miles on it, you could FEEL the slide barely popping back into battery, very weakly, that final 1/8”. Dirty gun, weak recoil spring, compromised grip…those 147’s are not going to run. I swapped the front sight back one that zerod the gun for 124’s and 115’s.
For whatever reason, maybe because the slide weighs more, my G48 seems to run pretty well with 124’s. I managed to induce a malfunction with 124 HSTs, but only by barely holding onto the gun with a few fingers. Still, with 115’s it just runs no matter what.
That’s all I got. Just thought I’d share. I love these guns. But getting them to run defensive ammo with the reliability you’d expect from a G17 or G19 has been a bit of an exercise. Or to put it more precisely—they can definitely be as reliable, but not with every ammo. If you’re just running ball for training, you might not ever run into these issues at all. If you ran a box of carry ammo through the gun right after you bought it, and since then you've put 1K rounds of ball through it, and put an extended baseplate on, it might be worth rechecking your carry ammo, especially with a one handed grip.