Glock 40 MOS Review: Powerful 10mm Performance

Why the Glock 40 MOS Deserves a Serious Look

I’ll be straight with you, I was skeptical the first time I picked up the Glock 40 MOS. A long-slide Glock in 10mm felt like overkill. But after months of carrying it in the field, running it through thick brush in Colorado, and testing it on everything from steel plates to actual backcountry conditions, I’ve completely changed my tune.

The Glock 40 MOS isn’t just a range toy. It’s a purpose-built outdoor handgun that straddles the line between hunting sidearm, trail gun, and serious bear-country companion, all without asking you to babysit a complicated platform.

This review covers everything: specs, real-world shooting feel, optics compatibility, hunting applications, and who this gun is actually built for.

Glock 40 MOS: Quick Specs at a Glance

That 6-inch barrel is doing a lot of heavy lifting here. More barrel means more velocity, and in 10mm, more velocity means the kind of energy that makes this handgun genuinely useful for hunting medium to large game.

First Impressions: Picking It Up for the First Time

The Glock 40 MOS is big. There’s no sugarcoating it. If you’ve held a Glock 17 or even a Glock 20, the 40 feels notably longer in the hand. The grip is the same full-size Gen 4 frame, familiar, textured, and confidence-inspiring, but that extended slide gives it a different visual presence.

What surprised me most was how naturally it points. Despite the size, the balance is good. The weight sits more forward than a standard Glock, which actually helps reduce muzzle flip during rapid follow-up shots, a real benefit when you’re shooting 10mm loads with actual energy behind them.

The MOS (Modular Optic System) cut is clean, machined into the rear of the slide, and accepts a wide range of red dot optics with included adapter plates. Out of the box, the pistol ships with a standard rear sight, but most serious users are going to mount an optic here, and the platform makes that dead simple.

The 10mm Caliber: Is It Actually Enough for Hunting?

Let me put this debate to rest: yes, 10mm is a legitimate hunting and field cartridge, especially in a 6-inch barrel.

With full-power hunting loads from reputable manufacturers, you’re looking at muzzle energy figures in the 750–800 ft-lbs range from the Glock 40’s long barrel. That’s significantly more than .357 Magnum from a comparable barrel, and well within the range for:

• Wild boar up to 200 lbs at reasonable distances
• Whitetail deer as a close-range/backup sidearm
• Black bear defense, widely recommended by wildlife agencies
• Large predators including mountain lions and feral dogs

Is it a deer rifle? No. But as a hunting sidearm or a dedicated handgun hunt setup, the Glock 40 MOS with the right ammunition is a serious tool, not a compromise.

If you’re building out a hunting or outdoors kit, you’ll want to pair this with quality ammunition and the right accessories. Browsing the selection at Golden Brothers Co is a smart starting point, they carry a solid range of handgun-ready gear for field use.

MOS Optics Platform: The Real Game Changer

Here’s where the Glock 40 separates itself from the Glock 20 (its shorter sibling): the MOS optics system makes mounting a red dot not just possible, but genuinely practical.

The system uses a recessed mounting plate that sits flush with the slide, protecting the optic and maintaining a lower mounting height than aftermarket milling. Four adapter plates are included, compatible with most popular red dot footprints.

Compatible optics platforms (factory plates):

• Trijicon RMR / SRO
• Leupold DeltaPoint Pro
• Docter / Noblex
• Shield RMS/SMS

For hunting and field use, a quality red dot dramatically speeds up target acquisition, especially in low-light conditions like early morning or late evening hunts. Running a 3.25 MOA dot on a Trijicon RMR gives you a combination that’s fast up close but still precise enough for 50-yard shooting on game.

The optic-ready platform is honestly the primary reason to choose the G40 over the G20 for hunting applications. It’s not an afterthought here, it’s central to the design intent.

Shooting the Glock 40 MOS: Range Day Breakdown

Accuracy

Using Underwood 180gr XTP handloads (a popular hunting choice), I was consistently shooting 3-inch groups at 25 yards offhand, and tighter from a rest. The long barrel gives the bullet more time to stabilize before leaving the muzzle, and you feel that in downrange consistency.

At 50 yards with an RMR mounted, I was keeping rounds on an 8-inch plate without effort. That’s genuinely useful accuracy for a hunting sidearm.

Recoil Management

10mm has a reputation for being snappy. The Glock 40 manages it better than you’d expect. The longer slide adds mass, which helps cycle the action more smoothly and reduces the felt snap compared to the G20. It’s not soft by any stretch, it’s still 10mm, but it’s controllable, and follow-up shots come back on target quickly.

The Gen 4 grip texture also helps here. Even with gloves on during a fall hunt, the pistol stayed firmly planted.

Trigger

Standard Glock Safe Action. Consistent ~5.5 lb pull with the characteristic pre-travel and reset. It’s not a competition trigger, but for field use it’s perfectly adequate, and aftermarket options are plentiful if you want to tune it.

Glock 40 MOS vs Glock 20: Which Should You Buy?

This is the question most people are asking, and the answer genuinely depends on your use case.

Choose the G40 MOS if: You’re primarily hunting, trail carrying, or want the best 10mm performance in a pistol format with an optic.

Choose the G20 if: You need something that can also serve as a concealed carry option or you’re in an environment where size matters more.

Holster & Carry Options for the Glock 40 MOS

Carrying a full-size hunting pistol requires different thinking than EDC. Most people running the G40 in the field are using:

• Chest holsters : Popular for bear country, keeps the gun accessible while wearing a pack
• OWB hip holsters, for day hikes or range trips
• Shoulder holsters, good balance between access and comfort on long treks

The extended barrel and MOS cut mean you need holsters specifically designed for the G40, not just any Glock-compatible option. Confirm optic-compatible fitment if you’re running a mounted red dot.

Best Ammunition for Hunting & Field Use

Ammunition selection matters more in 10mm than in many other calibers because the performance gap between standard and full-power loads is significant. The Glock 40’s long barrel rewards quality ammo.

For hunting:

• Underwood Ammunition 180gr XTP, one of the top choices for controlled expansion
• Buffalo Bore 180gr JHP, hard-hitting, deep penetrating
• DoubleTap 200gr WFNGC (hard cast), ideal for large game and bear defense

For bear defense (hard cast): Hard-cast bullets are preferred for large predators because they penetrate deeply without expanding, ensuring the round reaches vital organs through heavy muscle, fat, and bone.

For practice: Any quality 180gr FMJ from major manufacturers will do fine for training. Save the premium stuff for the field.

Who Is the Glock 40 MOS Built For?

Let’s be real about this. The G40 MOS is not for everyone. It’s a large, heavy handgun that requires commitment. But for the right person, it’s exceptional.

It’s the right gun for:

• Hunters who want a capable sidearm on the trail
• Outdoorsmen in bear country who want maximum 10mm performance
• Handgun hunters pursuing medium to large game
• Competitive shooters in USPSA Limited or Single Stack divisions who want a long-slide 10mm option

It might not be for you if:

• You need something compact for daily carry
• You’re new to semi-auto pistols and want something more forgiving to learn on
• Recoil sensitivity is a concern

Pros and Cons: Honest Assessment

Pros

• Exceptional muzzle velocity from the 6-inch barrel
• MOS optics platform is well-executed and practical
• 15+1 capacity is outstanding for a hunting sidearm
• Excellent trigger reset for a factory Glock
• Wide aftermarket support (holsters, triggers, optics)
• Proven Glock reliability in tough conditions

Cons

• Large size limits carry versatility
• Factory sights are basic, plan on upgrading
• Grip panels are non-interchangeable without aftermarket parts
• Not ideal for new shooters due to 10mm recoil

Final Verdict: Is the Glock 40 MOS Worth It?

After extended field use, I’d give the Glock 40 MOS a strong 9/10 for its intended purpose. As a hunting sidearm, trail gun, or dedicated field pistol, it’s hard to beat at this price point. The MOS system makes it genuinely optics-friendly, the 10mm caliber in a 6-inch barrel produces real terminal energy, and the Glock platform means you’re working with decades of proven reliability.

If you’re outfitting yourself for serious time in the field, whether that’s hunting season, backcountry camping, or just taking the outdoors seriously, the Glock 40 MOS deserves to be on your shortlist. Pair it with the right optic, the right ammunition, and quality field accessories, and it becomes a seriously capable tool.

FAQ: Glock 40 MOS, Your Questions Answered

Q: Is the Glock 40 MOS good for bear defense?
Yes. The 10mm caliber from a 6-inch barrel with hard-cast ammunition is widely considered adequate for black bear defense and is recommended by many wildlife professionals. For grizzly bear country, many experts still recommend larger bore rifles, but the G40 is a credible option when a pistol is all you have.

Q: What is the effective range of the Glock 40 MOS for hunting?
With full-power hunting loads and a mounted red dot, 50 yards is a realistic maximum for ethical hunting shots on medium game. Experienced shooters can push that to 75 yards on steel, but hunting requires a higher standard of precision.

Q: Can I use the Glock 40 MOS for concealed carry?
It’s technically possible with the right holster, but the 9.49-inch overall length and 6-inch barrel make it impractical for most concealed carry scenarios. It’s primarily a field gun.

Q: What red dot optics fit the Glock 40 MOS out of the box?
The included MOS adapter plates support the Trijicon RMR/SRO, Leupold DeltaPoint Pro, Docter/Noblex, and Shield RMS footprints. Third-party plates extend compatibility further.

Q: Is the Glock 40 MOS the same as the Glock 20?
They share the same caliber (10mm) and grip frame, but the G40 features a 6-inch barrel (vs 4.61″), longer slide, and the MOS optics-ready platform as standard. The G40 produces higher muzzle velocity and is more suitable for hunting applications.

Q: How much does the Glock 40 MOS cost?
MSRP is approximately $750–$850. Street price typically comes in around $650–$750 depending on the retailer and local market conditions.

Q: What is the magazine capacity of the Glock 40 MOS?
The Glock 40 MOS ships with two 15-round magazines for a total capacity of 15+1. Extended magazine options are available through aftermarket suppliers.

Q: Does the Glock 40 MOS come with a warranty?
Glock offers a limited lifetime warranty on all their pistols for original purchasers through authorized dealers.

For official information on handgun hunting regulations, safe firearm use in the field, and wildlife interaction guidelines including bear safety:

U.S. Fish & Wildlife Service – Hunting Regulations & Safety