Best Glock 43X Upgrades 2026: Optics, Triggers, Mags & Barrels Ranked

Not every upgrade matters equally. This is the order that delivers the most improvement per dollar spent on a 43X MOS carry gun.

The 43X MOS optic cut depends on the exact slide. Standard Slimline MOS slides use the Shield RMSc footprint; newer Slimline MOS-K slides accept Holosun K and RMSc optics without adapter plates. Standard RMSc cuts can also be modified for Holosun K optics by shortening or removing the recoil lugs, but that is permanent machining work. Check the item number sticker on your pistol case before ordering screws, plates, or a dot.

The Holosun 507K, EPS Carry, and SCS Carry use the Holosun K footprint and need a plate on unmodified standard Slimline MOS slides. A gunsmith can machine the RMSc recoil lugs for a lower K-footprint mount, but the adapter plate is the reversible path. Holosun leads the enclosed-emitter category with the SCS Carry and EPS Carry. The SIG ROMEO-X Compact Enclosed is the factory-grade alternative, and the Olight Osight SE is the value-tier enclosed option at one-third the price. For a broader comparison of pistol red dots across all platforms, see our pistol red dot guide.

The 43X's biggest factory limitation is its 10-round capacity. Swapping to a 15-round magazine delivers 50% more ammunition with zero change to the gun's external dimensions. This is the highest-ROI upgrade on the platform after an optic.

The Glock factory 15-round magazine (GL79269) is now the clear top pick for defensive carry. OEM Glock construction, factory warranty, and no steel mag catch required. The PSA Dagger Micro 15-round mag is the value leader for range use at half the price. The Shield Arms S15 still works but is no longer the default choice given its reliability track record and mandatory $35 steel mag catch. For defensive ammunition selection, see our best 9mm self-defense ammo guide.

The 43X trigger market is much thinner than the G19 market. The 43X/48 uses a different trigger bar geometry, so most Glock 19 triggers physically will not fit. The Overwatch Precision DAT is the standout flat-face option, and the Apex Action Enhancement Kit is the budget path that keeps the stock trigger shoe while meaningfully smoothing the pull.

A weapon light is non-negotiable on a home defense or nightstand gun. You cannot shoot what you cannot identify. The 43X has a slim accessory rail that accepts compact lights, but full-size options like the SureFire X300 create excessive overhang and destroy holster compatibility. Stick with lights designed for the slim rail. For a deeper comparison including full-size options, see our pistol lights guide.

The factory 43X sights are polymer and they are genuinely bad. The front blade cracks, the rear chips on holster re-insertion, and the three-dot pattern is slow to align in poor light. Replacing them with a steel set is one of the cheapest high-value upgrades on the platform, roughly $100-$130 for a permanent fix.

If your 43X is an MOS running a red dot, go suppressor height. The taller sights poke up into the optic window and give you a backup aiming reference if the dot ever goes dark or the glass gets occluded. If you are on a non-MOS 43X or you prefer a low-profile irons-only carry gun, pick a standard height set instead. Before buying a tall set, run the pistol red dot height checker to compare EPS Carry, 507K, direct-mount, and plate-height sight pictures.

The Radian Ramjet + Afterburner is the single biggest shootability upgrade you can make to a 43X. The stock gun is a snappy, muzzle-flippy pocket pistol that most shooters tolerate rather than enjoy. Install the Ramjet and the dot barely leaves the window between shots; splits tighten, follow-ups land on target, and the platform finally tracks like a compact 9mm instead of a subcompact trying to be one. Every upgrade on this page matters, but nothing else transforms the feel of the gun the way this one does.

The Afterburner comp mates to the Ramjet barrel with a tapered interface (no threads), so it is 50-state legal, cannot loosen under recoil, and requires zero thread locker or re-tuning. It runs the factory recoil spring and extractor, making this a true drop-in install with no gunsmithing. Read our hands-on Ramjet review for 300-round test results, and our Glock compensator guide for a broader look at comp options across the Glock lineup.

The honest tradeoffs: added overall length (verify holster clearance; the T.REX Arms Raptor fits the stock 43X Ramjet profile without ordering the 48 cut), plus more flash and concussion indoors. If this is your primary low-light home defense gun, weigh that against the shootability gain. For a dedicated range/training 43X or a carry gun used primarily outdoors, the Ramjet is a near-automatic yes.

Aftermarket slides are the lowest-priority upgrade for most 43X owners. The factory MOS slide already has an optic cut, and the functional gains from aftermarket slides are marginal compared to optics, triggers, and magazines. Consider a slide upgrade only if you want improved serrations, weight reduction, or a different optic footprint (RMR, ACRO) which also requires a matching optic swap.

Every upgrade that changes the external dimensions of your 43X requires holster verification. An optic requires an optic-cut holster. A weapon light requires a light-bearing holster. A compensator or aftermarket slide adds length. The factory 15-round magazine, PSA Dagger Micro, and Shield Arms S15 all maintain flush-fit dimensions, so none of them require holster changes.

The T.REX Arms Raptor accommodates a standard 43X with the Radian Ramjet installed without needing the Glock 48 or threaded-barrel holster option. For other holster brands, verify compensator compatibility before ordering. For a complete breakdown of holster options, see our concealed carry holster guide.