I am not a big fan of modifying or, better said - tuning, pistols. I have seen people changing springs, triggers, firing pins, guide rods and what not, spending big bucks and investing a lot of time just to end up with a pistol that wouldn't function reliably anymore. That's especially true for Glocks. Whether you like them or not, one thing is certainly undisputed: Glocks are simple and they just work and work and work. Now, if you start replacing reliable factory parts with fancy tuning pieces, you might well end up with a gun that will malfunction or even worse, be unsafe to handle.
That's no joke, I have seen people removing the firing pin safety on some pistols to supposedly get a better trigger pull. Of course, the firing pin safety is there for a good reason, please don't fiddle with it! Even the weird grip safety on the 1911s - just leave it there. Well, there might be one exception: some older pistols, such as for example certain models of the Browning High Power, come with a magazine safety. The trigger remains blocked until you insert a magazine. That will even prevent you from decocking the hammer without a magazine in the gun. It's really useless and I can recommend to happily remove that kind of nonsense.
Anyway, back to the topic: with all of the above said, there still are some mods that actually make sense for a Glock! I have been shooting Glocks since the early 90s and recently used a Gen 4 Glock 41 in the IDPA European Championship in 2020. I managed 3rd place in the CDP division, so I didn't fool around too much there. I also used a Glock 19 to win the CCP division and High Senior in the 2020 Siam International IDPA Championship.
Of course, what works for me won't necessarily do so for other shooters. Everything recommended here is purely subjective, as always, but it might set the tuning frenzy a little bit into perspective.
One - Sights
The factory sights are functional but they don't provide an optimally fast pick up of the sight picture. I am talking about competitive shooting where you want to get accurate hits on target as fast as possible. The more the front sight attracts the eye, the faster you will be in the end. Remember, too many super-fast misses of the zero-down won't do you any good on the scoreboard... I like a red or orange front sight for sports shooting. A fiber-optic front sight provides much improved speed and allows for that important positive feedback when acquiring a sight picture before the shot breaks.
I installed a fiber optic front sight from TruGlo and the steel version of the factory rear sight. Be careful, there are different heights of both front and rear sights and if you don't pay attention to that you will end up having your hits high or low. In my case, the ideal combination is a front sight height of 4.9 mm (measured from the slide surface) and a rear sight height of 6.9 mm (measured from the bottom of the dovetail), this combination made most 230 gr loads hit where they were supposed to, if I did my part that is.
I am not the youngest shooter anymore and my eyesight has never been really good. With those sights, I can still hit (mostly) what I am aiming at without loosing too much time. One more advice: be sure to loctite that front sight! If you don't, it will surely come loose in the most unfitting of moments.
Two - Trigger Guard Glocks and my hands have never really been friends. I am not sure what process Glock is following when designing their grips, but they certainly didn't consider anything resembling my hands when doing it. Man, compared to HK or Walther grips, those Glock handles are... well, anyway, it is what it is. The Glock 41 is rather beefy because if the 13-round capacity in .45 ACP. However, I got used to that. The most annoying part is the edgy trigger guard that grinds on your middle finger when applying a proper grip. Doing lots of practice repetitions, you will develop some hard skin on the concerned spot, haha.
So, out comes the file and after rounding those edges on both sides you will be much more comfortable. I prefer files over power tools since they give me more control over what I am doing. Remember, you can only remove material here, once it's gone, you can't add anymore.
Three - Trigger No no no, not what you might think... I didn't replace anything there, no fancy tuning trigger, lighter spring, polished connector, skeletonized striker or what. The trigger pull from the factory is about 24 N and I am quite happy with it, sorry about that. But the Glock triggers have one thing that really annoys me: when putting pressure on the trigger, the trigger safety does stick out from the trigger surface even when fully disengaged. I prefer a completely flat trigger surface.
So, I removed a little material from the front of the trigger safety to make it flat with the rest of the trigger when fully disengaged. It only takes a couple of 1/10s of a millimetre and leaves the trigger safety fully intact, of course, and gives a wonderful flat surface for your finger pad to apply constant pressure.
Four - Slide Lock Lever Simply replace the factory part with the slightly wider option. It will assure a positive slide release every time you have to reload from slide lock. For me, the extended lever doesn't interfere with my grip and I never accidentally pushed it down on the last shot. It just makes those reloads a little bit more consistent.
Five - Magazine Catch
No replacement necessary here. I just rounded the front edge of the factory catch somewhat to make it less painful to engage when practicing many repetitions.
Six - Grip I already gave a little rant about the grips, so just straight to the point here. I like to be able to grab my magazine positively when doing a tactical reload (i.e. with retention) or clearing an extended malfunction.
I added a sort of finger groove on each side of the grip allowing me to positively pull on that magazine should it be reluctant to come out for whatever reason. It's probably not needed to do that in most cases, but if it is, the possibility is there.
Seven - Magazines
At some point in time, Glock decided to change the design of the magazine and base plates making it almost impossible to field strip a magazine without tools and without using quite an amount of force. Why they did that, I have no idea.
Anyway, I made the locking lugs somewhat smaller, allowing the base plate to be removed without tools and without big effort. When you have a dirty magazine, it will pay off to clean it before using it again and I like to do that without a trip to the workshop.
Those were the seven mods I did on my Gen 4 Glock 41. I am perfectly happy with it and it makes a great IDPA CDP gun for me. Most of the mods described should translate easily to other Glock models, including Gen 5 variants.
If you are handy with tools and have a little experience in working with a certain precision, then those mods are not difficult to do. If you are not really experienced working on firearms, maybe better consult somebody who is or take your gun to a competent gunsmith.
Thanks for reading! Stay tuned for more...