The Glock 43X is the concealed-carry gun that finally made single-stack-thin comfort meet real capacity, and its aftermarket has exploded to match. Where a full-size Glock 17 build is about tuning a duty gun, a 43X build is about squeezing carry-gun performance out of a pocket-sized 9mm: more rounds, better sights, a light small enough to carry, and a holster you will actually wear. A few smart parts turn the 43X from a good carry gun into the one you stop shopping around for.
Below are the Glock 43X parts and accessories we would buy first, ranked by how much they matter for a carry gun. Everything here fits the standard Glock 43X and the optics-ready 43X MOS unless noted, and each pick is backed by a live price check across the retailers we track.
How we tested: Every pick here was run through our testing methodology. Minimum round counts, accuracy and reliability protocols, the failures that disqualify a gun. If we haven't shot it, we don't recommend it.
Glock 43X Upgrades at a Glance
| Category | Our Pick | Why It Makes the List |
|---|---|---|
| Magazine (the big one) | Shield Arms S15 | Turns a 10-round 43X into a 15-round gun in a flush steel mag |
| Steel mag catch | Shield Arms Z9 | Required companion to run steel mags without wear |
| Night sights | XS Sights R3D | Big, bright tritium front for a fast carry sight picture |
| Red dot optic | Holosun 507K X2 | The K-footprint dot sized right for the 43X MOS slide |
| Weapon light | Streamlight TLR-7 Sub | The sub-compact light purpose-built for slimline Glocks |
| Trigger | Tyrant Designs | Flat-face feel and a cleaner break for a carry gun |
| Barrel | Zaffiri Precision | Match accuracy, threaded and ported options |
| Holster | Concealment Express IWB | Molded Kydex that makes the 43X disappear |
Best Magazine Upgrade: Shield Arms S15
This is the upgrade that defines the Glock 43X. The factory magazine holds 10 rounds; the Shield Arms S15 holds 15 in the same flush-fit footprint, thanks to a steel body that replaces the polymer of a stock mag. That is a 50 percent capacity bump with no change to how the gun conceals — the single biggest reason people choose the 43X platform over a traditional single-stack. Buy several.
Don’t Skip: Shield Arms Z9 Steel Magazine Catch
If you run steel S15 magazines, swap the factory polymer magazine catch for the Shield Arms Z9 steel catch. Steel-on-steel is the correct pairing; leaving the polymer catch in place lets the metal mags wear it down over time and can cause drop-free issues. It is a nine-dollar part that protects a fifteen-dollar-per-mag investment — install it at the same time as your first S15.
Best Night Sights: XS Sights R3D
Factory Glock sights are plastic, and on a carry gun that is exactly where you do not want to cut corners. The XS Sights R3D gives you a bright tritium front dot ringed in a high-visibility photoluminescent circle for a fast, unmistakable sight picture in any light, with a blacked-out rear that keeps your eye on the front. It is one of the best carry sight setups you can buy for the 43X, and it co-witnesses with a red dot too.
Best Red Dot Optic: Holosun 507K X2
If you have the 43X MOS, a red dot is the fastest way to shoot it better under stress. The key is footprint: the 43X uses the smaller K-pattern cut, so you want the Holosun 507K X2, not the full-size 507C. It brings the same multi-reticle system, shake-awake, and solar backup as its bigger brother in a package sized for a slimline slide. Pair it with suppressor-height sights (the XS set above) so you keep an iron backup.
For more optic options and how to choose, see our best red dots for concealed carry guide.
Best Weapon Light: Streamlight TLR-7 Sub
A carry or nightstand 43X benefits from a light, but the full-size TLR-7 hangs off a slimline frame awkwardly. The TLR-7 Sub is the fix: Streamlight built it specifically for the 43X and 48, so it fits the frame cleanly at 500 lumens without turning your carry gun into a brick. Remember to buy a holster molded for a light-bearing 43X once you add it.
Best Trigger: Tyrant Designs
The stock 43X trigger is serviceable but spongy. A flat-faced drop-in from Tyrant Designs gives you a more consistent finger placement and a crisper break while keeping the factory safeties intact — a sensible choice on a carry gun. It is an easy at-home install and one of the upgrades you feel on the very first magazine.
Best Barrel: Zaffiri Precision
A match-grade drop-in barrel tightens groups and, in threaded form, opens the door to a compensator or suppressor. Zaffiri Precision makes well-regarded 43X barrels in flush-and-crown, ported, and threaded configurations with finishes to match a custom build. It is an optional upgrade rather than a must-have on a carry gun, but a worthwhile one if you shoot your 43X a lot or want to run a can.
Best Holster: Concealment Express IWB
The best carry gun in the world is useless without a holster you will actually wear. The Concealment Express IWB is molded Kydex with an adjustable cant and retention, a smooth draw, and a price that lets you buy the right rig instead of settling. Choose the version that matches your exact setup — bare gun, light-bearing, or optics-cut — because a universal holster is a compromise you will feel every day.
How to Prioritize Your Glock 43X Build
The 43X is a carry gun first, so spend money in the order that makes it carry better and shoot better under stress:
- Shield Arms S15 mags and the Z9 steel catch first. Capacity is the whole reason to run a 43X — start here, and install the steel catch at the same time.
- A good holster. The gear that decides whether you actually carry.
- Night sights. Cheap, easy, and they work when you need them most.
- A red dot if you have the MOS slide — remember the K footprint.
- A trigger and a light to round out the shooting experience and a defensive role.
- A match barrel last, for accuracy or suppressor use.
Still deciding on the gun itself? Compare it head-to-head in our Glock 43 vs 43X, Glock 48 vs 43X, Glock 43X vs Sig P365 XL, and Springfield Hellcat vs Glock 43X breakdowns, or browse the wider field in our best subcompact 9mm pistols and best compact 9mm pistols roundups. New to Glocks generally? Start with our best Glock pistols guide, feed it quality 9mm ammo, and if you also run a full-size Glock, see our Glock 19 parts and accessories list.
Frequently Asked Questions
What is the best upgrade for a Glock 43X?
The Shield Arms S15 magazine, paired with the Shield Arms Z9 steel magazine catch. Together they raise the 43X from 10 rounds to 15 in the same flush-fit footprint, which is the single biggest reason to run the platform. After that, a good holster and night sights are the highest-value upgrades for a carry gun.
Do I need the steel magazine catch to run Shield Arms S15 mags?
It is strongly recommended. The S15 has a steel body, and running steel magazines against the factory polymer catch wears the catch over time and can cause the mags to hang up. The Shield Arms Z9 steel catch is an inexpensive companion part designed to be installed alongside your first S15 magazines.
What red dot fits the Glock 43X MOS?
The Glock 43X MOS uses the smaller K-footprint optic cut, so you want a K-pattern red dot such as the Holosun 507K or 407K, or a Shield RMSc-footprint optic. The full-size 507C is too large for the slimline slide. Always confirm the footprint matches before buying.
Will a Glock 17 or 19 light fit the Glock 43X?
Not well. The 43X has a slim, shorter frame rail, so full-size lights like the Streamlight TLR-7 or TLR-1 do not fit properly. Use a sub-compact light designed for slimline Glocks, such as the Streamlight TLR-7 Sub, which is built for the 43X and 48.
Do Glock 43X parts also fit the Glock 48?
Many do. The 43X and 48 share the same slimline frame, so magazines, mag catches, triggers, holsters (frame-dependent), and many small parts interchange. The slide and barrel differ in length between the two, so slide- and barrel-specific parts are not cross-compatible.
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