The Glock 43X and SIG Sauer P365 represent the apex of modern micro-compact concealed carry handguns, offering defensive shooters distinct trade-offs between full-hand control and modular capacity efficiency.
The SIG Sauer P365 started the micro-compact genre of handguns, and when it comes to concealed carry, the P365 is an absolute titan. Built around its revolutionary 10-round magazine that fits in a one-inch-thick grip, it ended the dominance of the single-stack carry gun.
Other manufacturers quickly followed (thankfully), Glock included. Now when it comes to well-designed micro-compact guns, we have what some would call an “embarrassment of riches.” In that context, let’s look at the SIG P365 vs Glock 43X.
P365 vs 43X: Comparing Features and Performance
While Glock had introduced earlier models like the Glock 42 and Glock 43, these designs were eclipsed when the P365 came out in 2018. Other companies worked diligently to clone the P365 in one way or another, but Glock took a different route. Unveiling the Glock 48 and Glock 43X in 2019, Glock refined their approach to meet the demands of the modern concealed carry market.
These new guns kept the slim, single-stack magazines, increasing the capacity to 10 rounds while remaining fairly compact and easy to conceal.
The Glock 43X and Glock 48 series are very different guns. The smaller Glock 43X tends to align more with the P365, and the Glock 48 tends to align more with the P365XL or even the Macro series.
Today, we are looking at the differences between the SIG P365 and the Glock 43X in the context of concealed carry use.
SIG P365 vs Glock 43X
Why compare these two?
Comparing two random guns against each other has always seemed silly to me. Rather than treating these models as random competitors, it makes sense to compare them directly since they target the same segment of the market.
Both made it a point to hold ten rounds of 9mm in a flush-fitting magazine, and both have optics-ready options—the Glock 43X MOS and P365 Optics Ready.
The SIG P365 and Glock 43X are widely recognized as top-tier concealed carry options. They’re both vying for a spot in your IWB concealed carry holster.
Today, we will focus on the differences that make these guns unique and analyze each gun in depth.
Magazine Capacity and Aftermarket Upgrades
Admittedly, the P365 set the standard at 10 rounds in a flush-fitting magazine. SIG Sauer used an odd hybrid design — combining elements of both single-stack and double-stack magazines — to create a highly efficient, compact magazine. In contrast, Glock stuck with its traditional single-stack design.
While both guns hold 10 rounds in flush-fitting factory magazines, the efficiency of the P365’s design means its 12-round extended magazine is nearly the same length as the Glock’s 10-round magazine.
When comparing magazine capacity, it’s important to consider grip width: the P365’s grip measures exactly 1.00 inch, while the Glock 43X’s grip is slightly wider at 1.10 inches.
Glock 43X 15-Round Options: OEM and Aftermarket
While the Glock 43X traditionally shipped with 10-round polymer magazines,a Glock 43X 15 round magazine is now available both from the factory and the aftermarket, officially leveling the playing field against the P365.
Glock OEM 15-Round Magazines: Glock now offers factory 15-round slimline magazines with their signature steel-lined, polymer-over-molded design. This delivers 15+1 capacity without sacrificing factory reliability or needing a parts swap.
Aftermarket Steel Alternatives: Metal 15-round options—like the Shield Arms S15 or PSA Micro Dagger mags—remain popular flush-fit alternatives. Just remember: running steel Shield Arms mags requires swapping the factory polymer magazine catch for a steel one to prevent wear.
Modularity: FCU Architecture vs Traditional Frame
SIG Sauer has long focused on modularity in its designs. The P365 benefits from a removable Fire Control Unit (FCU)—a serialized chassis that houses the core firing components. This design allows for relatively simple swaps of frames, slides, and even caliber conversions (as seen in the .380 ACP variant).
The availability of an extensive aftermarket — covering upgrades for triggers, sights, magazine releases, and more — further enhances the P365’s versatility. You’ll notice my P365 is wearing a Wilson Combat grip module.
Glock’s approach is more traditional. With the Glock 43X, you can switch the slide (for example, by using a Glock 48 slide) and perform similar small upgrades such as swapping triggers, magazine releases, or sights.
While both platforms offer modularity, the P365’s FCU chassis architecture affords a greater degree of modularity overall.
Accuracy and Optics Compatibility
There is a lot to be said about the accuracy of small handguns. To be clear, the Sig P365 and Glock 43X are both going to be more accurate than the shooter behind them.
Both the Sig Sauer P365 and the Glock 43X are capable of engaging targets at distances up to 25 yards. Mechanically, they offer comparable levels of precision.
However, the P365’s all-metal, high-visibility sights have proven to be more durable and easier to use than Glock’s standard factory plastic sights.
Optics-Ready Variants: Slimline MOS vs. P365 OR
If you plan to run a micro red dot, both platforms feature factory-milled optics cuts, but they handle mounting differently.
Glock 43X MOS: Features a proprietary Slimline MOS cut. While it shares the basic screw layout of the Shield RMSc footprint, it retains raised rear recoil lugs. Because of this, the Glock 43 MOS cannot direct-mount Holosun K-series or EPS Carry optics out of the box. To mount those specific optics, the standard Glock 43X MOS requires a thin aftermarket adapter plate or manual modification to the slide’s rear lugs.
SIG P365 Optics-Ready: Features a native Shield RMSc footprint slide cut. It allows popular optics like the Shield RMSc, Holosun K-series, and Holosun EPS Carry to direct-mount flat to the slide without any adapter plates.
Ergonomics, Slide Bite, and Controls
Ergonomically, these small handguns perform as expected. The recoil is just barely enough to be called snappy. Both guns are fairly easy to control and shoot rapidly. You might not set world records with your Bill Drill, but you can reach a respectable enough time to post on the ‘gram.
In terms of controls, the guns are similar. Both use reversible magazine releases and tiny little slide locks. The magazine releases are easy to reach with a quick shift of the thumb, and I constantly pin down the slide lock of both guns with a thumb’s forward grip. Neither is mind-blowing, but they both work.
I do have some nitpicks and complaints with each gun.
Glock 43X Grip and Slide Bite
The Glock 43X features a slightly longer grip designed to accommodate the slightly longer magazine. This grip fits my whole hand and doesn’t leave a pinky hanging. The longer grip also ensures the magazine drops freely without requiring a grip adjustment.
My nitpick with the Glock 43X comes down to its firing ergonomics: slide bite. Lots of Glocks do this to me, and maybe we just don’t get along. It gets bad enough that it can draw blood after enough shooting.
What’s slide bite, you ask? The G43X doesn’t have a beavertail as such, so shooters with high, aggressive thumbs-forward grip techniques (especially if they have big mitts like me) often inadvertently push the web of their hand up above the tang. This, in conjunction with the G43X’s low bore axis (which means the slide sits low over the hand), results in the rear slide rail cutouts carving a path across the exposed meat and skin as the slide reciprocates.
Will you exsanguinate from it? Nope, but that doesn’t mean it’s comfortable! Consider installing an aftermarket extended beaver-tail sleeve.
Sig P365 Grip and Slide Lock Override
With the standard SIG P365, I have a hanging pinky with the flush-fitting magazine and need to add a magazine extension to have a grip that fully fits my hand. Also, with the P365, my finger and palm lock the magazine in place, so I have to release most of my grip to get it to drop free. That slightly longer grip on the G43X just works better for me.
The P365 doesn’t cause slide bite for me, but some shooters do complain of slide lock override instead.
What’s slide lock override, you ask? The geometry of the P365 is such that shooters using a high thumbs-forward grip (which is a lot of shooters) often rest their support side thumb directly over the slide-stop lever…which isn’t too big. That downward pressure can prevent the slide-stop lever from rising when the magazine follower pushes up after the final round is discharged. This results in the slide closing on an empty chamber instead of going to slide lock.
I didn’t have to deal with this issue, but it’s good to know it’s possible. Consider switching to a larger aftermarket grip module.
Reliability
While I have more rounds down the SIG P365 than the Glock 43X, I’m confident in saying both guns are highly reliable. Both the Sig Sauer P365 and the Glock 43X come from reputable manufacturers with longstanding track records.
I haven’t seen a difference in reliability between the two so far. Honestly, I doubt that one works much better than the other.
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Got Questions? We Have Answers
Is the Glock 43X or SIG P365 better for concealed carry?
Both handguns excel at concealed carry, but they serve different priorities. The SIG P365 offers a smaller overall footprint and higher factory capacity options (10, 12, and 15 rounds) via its compact frame and modular Fire Control Unit. The Glock 43X features a longer grip that accommodates all four fingers natively, providing superior recoil control and familiar Glock Safe Action mechanics.
Can you fit 15 rounds in a Glock 43X?
Yes. While factory Glock 43X magazines hold 10 rounds of 9mm, aftermarket flush-fit metal magazines (such as Shield Arms S15 or Palmetto State Armory Micro Dagger magazines) increase capacity to 15+1 rounds. Note: Using steel Shield Arms magazines requires installing an aftermarket steel magazine catch to prevent wear on the factory polymer catch.
Does the Glock 43X or SIG P365 have less recoil?
Recoil management between the two is very similar, but the Glock 43X generally feels slightly less snappy due to its longer grip frame (5.04 inches) and longer barrel (3.41 inches). The SIG P365 has a shorter 3.10-inch barrel and smaller flush grip, though adding an extended 12-round magazine or Wilson Combat grip module significantly improves control.
Final Verdict: Choosing Your EDC
Both are top-tier micro-compacts.
Glock and SIG Sauer approached the micro-compact market from different design angles. SIG set a new standard with the P365’s modular chassis and high-capacity magazine, while Glock delivered a slim, hand-filling pistol with the G43X.
Both handguns are reliable performers. If you want maximum concealment and modularity, go with the P365. If you prefer a full hand grip and classic Glock controls, the Glock 43X is a tough choice to beat.
If you are having trouble picking one, do what I did. Forget the versus part in SIG P365 vs Glock 43X and just get them both.
