Glock 39 Review – Subcompact .45 GAP Power in a Concealable Frame

The Glock 39 is a subcompact, semi-automatic pistol chambered in .45 GAP (Glock Auto Pistol) — a cartridge designed to deliver .45 ACP power from a smaller, more compact firearm. With a 3.43-inch barrel, 6-round magazine, and Safe Action® trigger system, it combines substantial stopping power with deep concealment potential.

Weighing roughly 22 ounces unloaded, the Glock 39 achieves a unique balance between concealability, durability, and reliability. While it sacrifices magazine capacity for a slimmer frame, its performance and handling make it one of the most capable subcompact .45-caliber handguns on the market.

Credits

What Makes the Glock 39 a Unique Subcompact .45 GAP Pistol?

The Glock 39 was introduced in 2004 as part of Glock’s effort to create a truly compact pistol chambered in .45 GAP — a cartridge developed by Glock and Speer to match the ballistics of .45 ACP while fitting in smaller frames. The idea was simple: deliver big-bore stopping power in a concealable size that even shooters with smaller hands could control.

In practice, the G39 succeeded at this goal, offering users a subcompact frame comparable to the Glock 26 but firing a much larger round. It became an appealing option for law enforcement backup, off-duty carry, and civilian concealed carry.

A Quick Look at Glock’s Legacy

Glock GmbH, the Austrian firearms manufacturer, has been a dominant name in the handgun world since the 1980s. Known for its polymer-framed pistols, Safe Action® system, and unmatched reliability, Glock revolutionized the handgun market by prioritizing simplicity and performance over aesthetics.

The Glock 39 continues this tradition. It belongs to the .45 GAP family, alongside the Glock 37 (full-size) and Glock 38 (compact), rounding out the lineup as the subcompact option for those who want discreet carry without sacrificing terminal effectiveness.

Intended Market and Purpose

The G39 was created primarily for concealed carry and backup use, designed to meet the needs of professionals and armed citizens who require a potent yet compact defensive handgun. Its lightweight frame and manageable dimensions make it ideal for deep concealment while retaining enough mass to control recoil effectively.

What Are the Glock 39 Specifications?

Core Technical Details

• Caliber: .45 GAP (Glock Auto Pistol)

• Barrel Length: 3.43 inches (87 mm)

• Overall Length: 6.50 inches (165 mm)

• Slide Length: 6.26 inches (159 mm)

• Height (with magazine): 4.17 inches (106 mm)

• Width: 1.30 inches (33 mm)

• Unloaded Weight: 22.22 oz (630 g)

• Loaded Weight: 27.87 oz (790 g)

• Magazine Capacity: 6 rounds (standard); optional 8- or 10-round extended magazines

• Trigger Pull: ~6.3 lbs (28 N)

• Action: Safe Action® striker-fired

• Sights: Fixed (white-dot front, notched rear)

Construction and Materials

• Frame: Polymer with integrated steel inserts for rigidity

• Slide: Hardened steel with corrosion-resistant finish

• Barrel: Cold hammer-forged with polygonal rifling for improved longevity and accuracy

• Recoil Spring: Dual-spring system to mitigate recoil and slide wear

• Accessory Rail: Standard Glock universal rail for lights and lasers

How Is the Glock 39 Designed for Durability and Practical Carry?

Frame and Build Quality

The polymer frame provides the Glock 39 with both strength and reduced weight, a core reason for its concealability and ease of carry. Glock’s proprietary polymer is resistant to corrosion, solvents, and temperature extremes, ensuring consistent function in all conditions.

The steel slide — coated with Glock’s nDLC finish — is exceptionally durable and maintains a smooth cycling action even after extended shooting sessions.

Ergonomics and Grip Feel

Despite its small frame, the G39 feels secure in the hand. Its molded finger grooves and thumb rest improve control during recoil, while the texture provides sufficient traction without being abrasive. Shooters with medium or smaller hands find it particularly ergonomic.

The grip angle remains Glock’s familiar 22 degrees, allowing natural pointability and rapid target acquisition.

Controls and Safety

The Glock 39 maintains the standard Safe Action® System, consisting of:

• Trigger safety – disengages only when pressed deliberately.

• Firing pin safety – prevents striker movement until trigger is pulled.

• Drop safety – ensures the firearm won’t discharge if dropped.

All controls — the mag release, slide stop, and takedown levers — are intuitive and placed identically to other Glock models, ensuring training consistency across platforms.

Optics and Accessory Compatibility

The G39, being a Gen3 design, does not feature MOS (Modular Optic System) compatibility. However, it does include a short accessory rail, allowing users to mount compact lights or lasers. Upgrading the stock sights to night or fiber optic options significantly enhances low-light capability.

What Are the Glock 39’s Variants and Closest Comparisons?

Model Lineage

The Glock 39 is the subcompact member of the .45 GAP family, following the:

• Glock 37 (full-size) – 10-round capacity, 4.49-inch barrel

• Glock 38 (compact) – 8-round capacity, 4.01-inch barrel

• Glock 39 (subcompact) – 6-round capacity, 3.43-inch barrel

All three share the same operational design, magazine compatibility, and internal parts standardization, but differ in grip size and capacity.

Comparable Firearms

• Glock 30 (.45 ACP): Slightly larger and heavier, but with a higher magazine capacity.

• Springfield XD-S .45: Similar concept — slim, subcompact .45 — but lighter and flatter.

• Sig Sauer P365 .45 (conceptually similar): A modern micro-compact with higher capacity, though not yet available in .45.

• Kahr PM45: Another ultra-compact .45 with low capacity but similar concealment intent.

Compared to these, the Glock 39 stands out for its reliability, simple maintenance, and proven design lineage.

How Does the Glock 39 Perform on the Range?

Accuracy

For a subcompact pistol, the Glock 39 delivers excellent accuracy within defensive distances (7–15 yards). The 3.43-inch barrel provides stable velocity and precision, with shooters regularly reporting tight groups of 2–3 inches at 10 yards.

The smooth trigger break and short reset enable rapid follow-up shots once the shooter adapts to the heavier recoil.

Recoil and Control

Recoil is snappy but controllable — expected from a small .45-caliber handgun. The dual recoil spring assembly reduces slide impulse, and the polymer frame flexes slightly to absorb shock. With proper grip, muzzle rise remains manageable even under rapid fire.

Reliability and Endurance

Reliability remains Glock’s strongest trait. Thousands of users report flawless cycling across hundreds or even thousands of rounds. The G39 runs well on both ball and defensive ammunition, including +P-rated loads.

Trigger Feel

The G39 uses Glock’s standard 6.3-lb Safe Action trigger: smooth, consistent, and with a crisp reset. While not designed for competition, it’s well-suited for defensive accuracy and muscle memory under stress.

What Ammunition Works Best with the Glock 39?

Ideal Grain Weights

The .45 GAP cartridge is optimized for 185- to 230-grain bullets, mirroring the performance of .45 ACP at slightly reduced overall cartridge length.

Defensive Loads

• Speer Gold Dot 200gr JHP (.45 GAP) – engineered for this caliber, excellent expansion and penetration.

• Federal HST 185gr JHP – consistent terminal performance with moderate recoil.

• Hornady Critical Defense 185gr FTX – excellent reliability in short barrels.

Training and Range Loads

• Speer Lawman 200gr FMJ – great for realistic practice with duty-equivalent recoil.

• Federal American Eagle 185gr FMJ – affordable and clean-burning.

Known Issues

The main challenge remains ammunition availability. The .45 GAP is a niche cartridge, not as widely stocked as 9mm or .45 ACP.

However, for owners who stock up online or reload, this is a minor inconvenience given the round’s ballistic performance.

How Suitable Is the Glock 39 for Different Uses?

Is the Glock 39 Ideal for Concealed Carry?

Yes — this is where it truly shines. With its short barrel, low profile, and reduced weight, the G39 disappears easily under a shirt or jacket. Its reliable function and controllable recoil make it one of the few subcompact .45-caliber pistols you can confidently carry daily.

Is It a Good Choice for Home Defense?

While capacity is limited to six rounds, the Glock 39’s stopping power and simplicity make it effective for home defense. Paired with an attached weapon light, it’s an excellent close-quarters option for those trained with compact pistols.

Is It Suitable for Competition?

Not particularly. The G39’s shorter sight radius and capacity limit its competitiveness in IDPA or USPSA divisions, though it can serve as a compact backup for those running .45 GAP systems.

Is It Reliable for Outdoor or Field Carry?

Yes — it’s light, corrosion-resistant, and rugged enough for outdoor carry. The .45 GAP round offers reliable penetration, though it’s better suited for defensive use against threats rather than hunting.

Is It a Range Toy or Professional Tool?

While enjoyable to shoot, the Glock 39 is fundamentally a professional tool — designed for serious defensive use rather than recreational range time.

What Are the Best Holsters for the Glock 39?

A quality Glock 39 holster is essential for secure carry and comfort. Each holster below is molded from durable polymer (Boltaron) for consistent retention and long-term durability.

Cloak Tuck 3.5 IWB Holster

The Cloak Tuck 3.5 Glock 39 holster offers adjustable cant and ride height for deep concealment and maximum comfort during daily wear.

Belt Holster

A belt Glock 39 holster provides strong-side carry with firm retention and an accessible draw, ideal for open carry or range use.

OWB Paddle Holster

An OWB paddle Glock 39 holster enables quick attachment and removal with excellent draw speed for defensive practice.

Swivel Drop Leg Holster

A swivel drop leg Glock 39 holster positions the pistol on the thigh for fast access during tactical or field operations.

Chest Holster

A chest Glock 39 holster offers stable carry for outdoor use, keeping the firearm accessible while seated or moving through rugged terrain.

Hook & Loop Holster

A hook & loop Glock 39 holster allows mounting flexibility — ideal for vehicles, safes, or modular packs.

What Are the Glock 39’s Pros and Cons?

Pros

• Compact and lightweight for a .45-caliber pistol

• Excellent reliability and build quality

• Manageable recoil despite size

• Ideal for deep concealment

• Glock’s proven Safe Action® trigger system

• Accurate for defensive distances

Cons

• Limited 6-round capacity

• Ammunition availability and cost

• No Gen4 or Gen5 version

• Basic factory sights

• Noticeable recoil for inexperienced shooters

What’s the Final Verdict on the Glock 39?

Who Should Consider the Glock 39?

The Glock 39 is an excellent choice for concealed carriers, law enforcement backups, and Glock enthusiasts who want serious .45-caliber power in a discreet subcompact form. It’s designed for professionals who prioritize reliability, control, and consistent performance in a small package.

Value and Long-Term Ownership

Though the .45 GAP caliber limits mainstream adoption, the Glock 39 remains a collectible yet practical firearm. Its low maintenance needs, proven durability, and crisp operation make it a long-term investment for defensive shooters.

Final Recommendation

The Glock 39 is a small gun with serious authority — a true subcompact powerhouse that embodies Glock’s reliability and engineering precision. For those willing to commit to the .45 GAP round, it’s one of the most capable and underrated defensive pistols ever made.