Glock 17 Gen 4 MOS

The Glock 17 Gen 4 MOS is a full-size 9×19mm pistol that combines Glock’s proven Gen 4 platform with the Modular Optic System (MOS), allowing for the mounting of select reflex optics. Trusted worldwide for its reliability and adaptability, the G17 Gen 4 MOS is commonly referenced for duty, training, and competition contexts.

Product Description | Specs Glock

The Glock 17 Gen 4 MOS features Glock’s Safe Action® striker-fired system along with factory-cut slide optics compatibility. Built on the Gen 4 frame, it includes ergonomic improvements such as interchangeable backstraps and an updated recoil spring assembly, while the MOS configuration adds versatility for red dot users.

G17 Gen 4 MOS Specifications:

• Caliber: 9×19mm
• Capacity: 17+1 rounds
• Barrel Length: 4.49 inches
• Overall Length: 7.95 inches
• Weight (Unloaded): Approx. 22 oz
• Action: Striker-fired
• Frame Size: Full-size
• Slide: MOS-cut with adapter plates
• Finish: Tenifer / matte black

Features

The G17 Gen 4 MOS includes all standard Gen 4 enhancements plus optics-ready capability:

• Modular backstrap system for customized grip fit
• MOS slide cut for compatible reflex optics
• Reversible magazine release
• Dual recoil spring assembly for reduced recoil
• Rough Textured Frame (RTF) for improved grip
• Proven Glock barrel design
• Durable, corrosion-resistant finish

These features make the Gen 4 MOS a flexible option for shooters who prefer slide-mounted optics.

What the Glock 17 Gen 4 MOS Is Made Of

The Glock 17 Gen 4 MOS is constructed using Glock’s established materials for durability and longevity:

• Frame: High-strength polymer
• Slide: Steel with MOS cut and protective coating
• Barrel: Cold hammer-forged steel
• Internal Parts: Hardened steel components

This construction supports consistent performance in a wide range of conditions.

Glock 17 Gen 3 vs Gen 4 MOS

When comparing the Glock 17 Gen 4 MOS to the Gen 3 model, several differences are notable.

Gen 3:

• Fixed grip size
• Single-sided magazine release
• No optics-ready slide

Gen 4 MOS:

• Interchangeable backstraps
• Reversible magazine release
• Improved grip texture
• Dual recoil spring system
• Factory MOS slide cut

Glock 17 Gen 4 MOS vs Gen 5 MOS

The Gen 4 MOS is often compared with the newer Gen 5 MOS.

Gen 4 MOS Features:

• Modular backstrap system
• Finger grooves
• Reversible magazine release
• MOS optics compatibility

Gen 5 MOS Improvements:

• Glock Marksman Barrel
• Ambidextrous slide stop
• Flared magazine well
• No finger grooves

The Gen 4 MOS remains relevant for users who prefer the Gen 4 grip style and parts compatibility.

Compatibility

The Glock 17 Gen 4 MOS is compatible with a broad range of Glock accessories:

• Magazines: Compatible with Gen 3, Gen 4, and Gen 5 magazines
• Holsters: Fits most Glock 17 holsters (optic-compatible recommended)
• Optics: Compatible with select red dots via MOS plates
• Sights: Standard Glock dovetail cuts
• Parts: Extensive aftermarket support

Always verify compatibility when selecting accessories.

Glock 17 Gen 4 MOS Pros and Cons

Pros

• Optics-ready MOS slide
• Proven Glock Gen 4 reliability
• Modular grip system
• Wide aftermarket compatibility
• Balanced recoil and control

Cons

• No ambidextrous slide stop
• Finger grooves may not suit all users
• Lacks Glock Marksman Barrel of Gen 5

FAQs

What does MOS mean on the G17 Gen 4?
MOS stands for Modular Optic System, allowing the mounting of compatible reflex sights using adapter plates.

Is the G17 Gen 4 MOS different from the standard Gen 4?
Yes, the MOS version includes a factory-cut slide designed for optics.

Is the G17 Gen 4 MOS commonly used with red dots?
Yes, it is designed specifically to support slide-mounted optics.

DISCLAIMER

Duty Pistols Inc provides aftermarket and compatible parts and components for GLOCK pistols. We operate independently and do not represent, endorse or have any connection with GLOCK, Inc. or GLOCK Ges.m.b.H.

GLOCK, Inc. and GLOCK Ges.m.b.H own the trademark “GLOCK” and other related marks. We mention “GLOCK” only to identify parts and products that fit or work with GLOCK pistols.