Sig P365 vs Glock 43X: The Two Default Carry Guns, Decided

The gun that changed the size chart, and the answer to it

When Sig began shipping the P365 in 2018, it reset what people expected from a small 9mm. Ten rounds in a gun about the size of the single-stacks it replaced was the headline, and its magazine, which Wikipedia describes as an offset double-stack, set the pattern for the class.

Glock's answer arrived in 2019 with the 43X and the 48. The 43X took the slide of the single-stack G43 and put it on a taller frame with a wider 10-round magazine. Gun Digest called it essentially a Glock 43 upper on a taller frame. It wasn't trying to be smaller than the P365. It was trying to be easier to hold.

That's still the cleanest way to frame the choice. The P365 is the more compact gun. The 43X is the longer-gripped gun. Both hold 10 rounds in their standard magazines. Everything else follows from size.

Size first, because that's why you're buying one

P365 figures come from published specifications summarized on Wikipedia, which lists small differences between sources (for example, 147 mm vs 150 mm length). Glock 43X figures come from Glock's own spec page. Treat a tenth of an inch either way as noise, and check the maker's sheet for the exact variant you're looking at, since Sig sells many P365 configurations.

The meaningful gap is height: about three-quarters of an inch. That's grip. The 43X grip is long enough for most adult hands to get all three fingers on it. The base P365 grip with a flush magazine leaves many shooters' pinky finger hanging, which is why extended baseplates and 12-round magazines are so popular on it.

Length is the second gap. The 43X is longer by roughly 0.7 inch, mostly barrel and slide. That's a little more sight radius and a little more muzzle to tuck under a waistband.

Width is nearly a wash. Neither is a fat gun.

Capacity: same on paper, different in practice

Out of the box, both hold 10+1. The difference is what each one lets you grow into.

The P365's grip takes longer factory magazines. Wikipedia notes the frame accepts 10-, 12- and 15-round magazines, and Sig's own page describes the line as running from 10+1 up to 21+1 across the family. Fit a 12-rounder and you get a pinky-length grip with two extra rounds; fit a 15-rounder and you've built something closer in grip length to a compact. Magpul also makes AMAG steel P365 magazines in 10, 12 and 15 round sizes, sold through Ammunition Depot's handgun magazine section.

The 43X stays at 10 from Glock. Glock's slimline magazines are 10-rounders and, per Gun Digest, are wider than G43 magazines, so they aren't backward compatible with the original G43. Shield Arms makes the S15, a 15-round steel magazine for the 43X and 48, and some packages include a replacement magazine catch. That's a well-known upgrade, but it is third-party, so test it hard in your gun.

If capacity is the deciding factor, the P365 gives you more factory routes to more rounds. If you're happy at 10, it doesn't matter.

In the hand

Grip. This is where the 43X earns its fans. Its longer frame means a full grip with the standard magazine. Glock lists its trigger pull at 24 N, and its grip is the familiar Glock angle, which some people love and others find points high.

The P365 is shorter, so with the flush magazine it's a two-finger grip for many shooters. Sig made the P365 modular, with a removable fire control unit similar to the one in the P320, according to Wikipedia. You can move that FCU into a longer or differently shaped grip module, which is how many owners end up with a P365 that feels like a 43X anyway. Our P365 upgrade path covers that.

Trigger. Both are striker-fired with no external hammer. Trigger feel is personal and hard to describe from spec sheets, so we won't pretend otherwise. Try both if you can, ideally at a range that rents them.

Recoil. A heavier gun with a longer grip generally gives more control, and the 43X is slightly heavier and has more to hold. Short, light 9mms are snappy by nature; our micro-9 recoil management guide applies to both.

Optics and the cost of the cut

Both are widely sold optic-ready. The 43X MOS uses Glock's Modular Optic System. Many P365 variants, including the X and XMACRO lines, come optic-ready or with Sig's ROMEO-X dot installed; Sig's model page says the P365 is also available with that optic pre-installed and zeroed.

Here's the honest catch: a red dot adds cost and height. If you're adding one, budget for the optic, the right mounting hardware, and an optic-cut holster. Read our take on red dots on carry guns before deciding if it's worth it for you.

Holsters and spare magazines

Both guns have deep holster support. For example, DeSantis makes its Kydex Mean Streak IWB holster in versions for the Glock 43X MOS and the P365 with red dot. Check that any holster matches your exact model, light and optic.

For a spare magazine, 1791 Gunleather's leather SnagMag clips come in Glock 43X/48 and P365 12-round sizes, and can be worn in the waistband or a pocket.

Which P365, which 43X?

Part of the confusion in this matchup is that "P365" is a family, not a gun. Wikipedia lists the P365 XL (June 2019), the SAS (October 2019), the P365X (2021), the .380 version (announced February 2022), the XMACRO (2022) and the FUSE (June 2024), among others. Because the fire control unit moves between frames, Sig can mix slides and grips into many combinations.

This article compares the base P365 with its 3.1-inch barrel and 10-round flush magazine, because that's the gun most people mean. If you're looking at a longer-gripped P365X or XL, the size gap with the 43X narrows a lot, and our P365 vs XL vs XMACRO guide is the better read.

The 43X family is simpler. There's the 43X and the optic-ready 43X MOS, plus finish and sight variants. If you want a longer slide on the same frame, that's the Glock 48. If you want a shorter grip, that's the original single-stack Glock 43, which uses different magazines.

Living with each one

Concealment. The P365's shorter grip is the main reason it disappears more easily, especially in appendix carry or with light clothing. The 43X's longer grip is the part most likely to print.

Reliability and break-in. We haven't tested either gun, and we won't make claims about round counts. Both have large user bases. Whatever you buy, run a meaningful amount of your carry ammunition through it and every magazine before you trust it. Our 200-round checklist is a practical framework.

Parts and support. Glock's parts support is famously deep, and the 43X shares components with the 48. Sig's P365 aftermarket has become enormous too, with grip modules, slides, sights and magazines.

Hand strength. Small, stiff-sprung guns can be hard to rack. If that's a concern, handle both before buying, and see our easy-rack carry guns guide.

The decision

Pick the Sig P365 if:

• Smallest overall size matters most: you dress lightly, are slim, or carry in deep concealment.
• You want factory 12- and 15-round magazines that fit the same gun.
• You like the idea of a modular gun you can reconfigure with different grips and slides.
• You want a manual-safety option from the factory.

Pick the Glock 43X if:

• You want a full grip with the standard magazine and have medium to large hands.
• You prefer Glock's simple design and parts support.
• A slightly longer barrel and sight radius appeals to you.
• You're satisfied with 10 rounds, or happy to proof aftermarket 15-rounders.

Consider something else if you want 13 rounds at single-stack-like width with a thumb-safety option; the S&W Shield Plus is the obvious alternative, and we compare it to the 43X separately. Or read our P365 vs Hellcat Pro breakdown.

Before either one rides on your belt

Shoot enough of your chosen defensive ammunition to trust it. A popular option for short barrels is Speer Gold Dot 9mm 124-grain +P; our guide to choosing 9mm defensive ammo explains how to pick. Keep the gun in a quality holster that fully covers the trigger, and store it securely whenever it's off your body.

Editorial note: This is an independent editorial overview built from manufacturer specifications, retailer listings and published sources. We have not performed hands-on testing of the products discussed, and nothing here is a performance guarantee. Verify specifications, compatibility and the law where you live.

Affiliate disclosure: Some links on this page are affiliate links to Ammunition Depot. We may earn a commission if you buy through them, at no extra cost to you. Our editorial choices are not influenced by commissions. Check current price, stock and specifications directly with the retailer.