Same Slide, Different Grip
The Glock 43 and Glock 43X look nearly identical from the top half. Same slide length, same barrel, same sight dovetails. The difference is the frame — and that one difference changes magazine compatibility entirely.
This guide maps every major component and tells you exactly what swaps between the two and what does not. If you own one and want to buy parts for the other, or you are building on an aftermarket frame, this is the reference.
The Core Difference: Frame Size
The Glock 43 has a shorter grip that holds a flush-fit 6-round magazine. The Glock 43X uses the Slimline frame with a longer grip that accepts a 10-round magazine. Slide dimensions, barrel specs, and internal parts are shared between the two. The frame is what separates them.
Think of it this way: the Glock 43X is a Glock 43 slide sitting on a Glock 48 grip. That grip length is the source of every compatibility question.
Slides: Fully Interchangeable
A Glock 43 slide fits a Glock 43X frame, and a Glock 43X slide fits a Glock 43 frame. The slide dimensions are identical — same width, same length, same rail interface. This applies to both OEM and aftermarket slides.
If you are shopping for an upgraded slide, any slide listed as compatible with the Glock 43 will also work on the 43X. An RMSc cut black DLC slide for the Glock 43/43X drops onto either frame with no modifications. The same goes for stripped slides — browse the full Glock slides catalog and filter by Glock 43 or 43X. The results are the same. A stripped RMSc window slide needs a slide completion kit and a barrel to finish. For what is worth upgrading, see our Glock 43 slide upgrade guide.
If you want a slide that comes ready to install with barrel, sights, and internals already fitted, the assembled windowed slide for the Glock 43/43X works on both the Glock 43 and 43X frame.
Barrels: Fully Interchangeable
Both pistols use the same 3.41-inch barrel with the same locking block geometry and hood dimensions. Any barrel made for the Glock 43 fits the Glock 43X, and vice versa. This includes threaded barrels — the 9mm nitride threaded barrel is cut 1/2x28 and fits either frame. Aftermarket barrel options for the 43 and 43X covers the rest.
Aftermarket barrels like the 9mm oil slick crown cut barrel for Glock 43/43X are sold as dual-compatible because the barrel specs are identical. If you want a deeper look at finish options — nitride, TiN, DLC, oil slick — the barrel finish comparison guide covers the differences.
Recoil Spring Assembly: Fully Interchangeable
The Glock 43 and 43X use the same captive recoil spring assembly. Same guide rod length, same spring weight. This is a direct swap with no modification needed. Aftermarket guide rods and spring kits marketed for one will work in the other.
Magazines: Not Interchangeable
This is the one major exception. The Glock 43 ships with a 6-round single-stack magazine. The Glock 43X ships with a 10-round magazine that is physically longer to match the extended grip.
A Glock 43X magazine will not seat in a Glock 43 frame. It is too long — the baseplate hits the bottom of the grip before the mag locks in. A Glock 43 magazine can physically insert into a Glock 43X frame and will lock in place, but it leaves a visible gap at the bottom of the grip and reduces capacity to 6 rounds. It works in an emergency but defeats the purpose of the longer grip.
If you are running a Glock 43X and want to use Shield Arms S15 metal magazines for 15-round capacity, those are specific to the 43X/48 frame. They will not fit the Glock 43. The same frame split applies to accessories — a 43X/48 magwell will not fit a 43 either.
Sights: Fully Interchangeable
Both models use the same sight dovetail dimensions, and the same optic cut — the RMSc footprint. Which red dots fit applies equally to both. Any aftermarket sights — night sights, fiber optic, suppressor-height — that fit the Glock 43 will fit the Glock 43X. The rear dovetail is 6.5mm and the front is the standard Glock narrow tenon. No difference between the two.
Trigger and Lower Parts: Mostly — but Check the Kit
The trigger with trigger bar, connector, slide lock and spring, trigger pins, slide stop lever and locking block are shared between the Glock 43 and 43X. Upgrade the trigger on one and the same trigger works in the other.
Two parts do not cross over: the magazine catch and the trigger housing. Their geometry differs between the single-stack Glock 43 frame and the longer 43X/48 frame, so a lower parts kit built for one will not drop into the other. This is the part most people get wrong, because everything around those two components is identical.
It matters when you buy a kit. Our Glock 43 lower parts kit is single-stack only — it will not work in a 43X or 48 frame. The Glock 43 / 43X / 48 lower parts kit ships with two magazine catches, one for each frame length, so a single kit covers all three builds. The 43X and 48 share a frame, so they take the same catch.
Compensators: Interchangeable
Because both pistols share the same barrel and slide dimensions, any compensator that fits a threaded Glock 43 barrel fits the 43X. Thread pitch on aftermarket barrels is 1/2x28 for both. The Faxon EXOS-533 compensator is designed for the Glock 43, 43X, and 48 — it matches the slide width of all three models. Same story for any comp sized for the Slimline platform.
Quick Reference: What Swaps and What Does Not
| Component | Interchangeable? | Notes |
|---|---|---|
| Slide | Yes | Identical dimensions |
| Barrel | Yes | Same 3.41" barrel, same lug |
| Recoil spring | Yes | Same captive assembly |
| Sights | Yes | Same dovetail cuts |
| Trigger, connector, slide lock, pins | Yes | Shared |
| Trigger housing | No | Geometry differs by frame |
| Magazine catch | No | 43X/48 take a different catch |
| Compensator | Yes | Same barrel thread and slide width |
| Magazine | No | Different lengths — 6-round vs 10-round |
The Bottom Line
Almost everything above the frame rail is shared between the Glock 43 and Glock 43X. Slides, barrels, recoil springs, sights, triggers, and compensators all swap directly. The parts that do not cross over are magazines, the magazine catch and the trigger housing — all tied to the different grip length. If you are shopping for upper components, buy for either model with confidence. Laws vary by state — verify local regulations before purchasing.
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