Glock
Glock 43X MOS
The slim, optic-ready 10+1 single stack that became the default modern carry gun — and the canvas for this entire build.
Overview
The 43X MOS pairs a 3.41" barrel and a full-length grip with a factory optic cut. That grip is the whole reason this platform works: you get a full firing grip with all fingers on the gun while the slide stays under an inch wide. Add the MOS cut and it becomes the most upgradeable slim carry pistol on the market.
Why I chose this
I wanted one pistol that could be a training gun, a range gun, and an appendix carry gun without compromise. The MOS cut meant I wouldn't have to pay for slide milling later, and the aftermarket for this frame is deeper than anything else in the slim category.
Real world performance
Roughly 6,400 rounds through mine across steel, factory 115gr, and 147gr defensive loads. Two stoppages total, both from a worn factory magazine spring in the first 500 rounds. Recoil is snappier than a 19 but entirely manageable once the comp went on.
Concealed carry impact
This is the baseline everything else is measured against. 1.10" wide printing-wise means it disappears under a t-shirt in AIWB with a good wedge. Full grip length is the one thing that can print when you bend — a claw on the holster solves it.
Kourtni's personal notes
Not marketing copy — carry experience
I carried a 26 for two years and always fought the grip. The 43X fixed that in one afternoon — my pinky finally has somewhere to live and my draw stopped being a negotiation. The stock trigger is fine, not great; I'd shoot 500 rounds before spending a dollar on one. The thing nobody warns you about: the factory 10-round mags are the weak point of the gun, not the gun itself. Budget for magazines before you budget for anything shiny.
Pros
- Full-hand grip in a sub-1.1" wide package
- Factory optic cut — no milling required
- Enormous aftermarket support
- Glock reliability and parts availability
Cons
- Factory 10-round magazines are the weak link
- Stock trigger is serviceable but uninspiring
- Snappier recoil impulse than a double stack
Installation tips
- Shoot it bone stock for at least 500 rounds before modifying anything.
- Log every stoppage with mag number, ammo, and round count — you'll need that baseline later.
Lessons learned
- Nearly every 'gun problem' I diagnosed in the first year was a magazine problem.
- Sights and trigger time beat parts. Every time.
Mistakes to avoid
- Buying every part on day one before you know how the gun runs stock.
- Assuming 43X and 48 parts are always cross-compatible — slides and barrels are not.
Alternative products
Glock 48 MOS
Same frame, longer slide and sight radius. Better shooter, slightly harder to conceal.
Sig P365 XMacro
More capacity, integrated comp, wider. My pick if capacity outweighs slimness.
S&W Shield Plus
Cheaper entry, smaller aftermarket, better stock trigger.
Upgrade path: Magazines → sights/optic → light → holster → comp/barrel → cosmetic
Frequently asked questions
43X or 48?+
Same frame. Take the 48 if you shoot more than you carry; take the 43X if it lives on your body all day.
Do I need the MOS version?+
Yes, if there's any chance you'll run a red dot. Slide milling costs more than the price difference.
Is the Gen 5 trigger enough?+
For carry, yes. Fix your grip and your dry fire before you buy a trigger.
Overall recommendation
The right foundation for a modern slim carry build. Buy the MOS version, buy good magazines, then start upgrading.
Related
Related products
Shield Arms
Shield Arms S15 Magazine
15 rounds in a 43X-sized magazine. A 50% capacity increase for under $50 — the single best upgrade on this list.
$45
MSRP $55
Holosun
Holosun HS507K X2
The carry-sized red dot that made pistol optics normal — multi-reticle, shake awake, and priced like it isn't premium.
$289
MSRP $340
Tulster
Tulster Oath IWB Holster
The part that determines whether you actually carry this gun every day. Cut for the optic, light, and comp.
$79
MSRP $89
Free download
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Price drops, revisions, and recalls on everything in this build — sent only when something actually changes.