Glock 31 Gen 4 OEM Slide

Glock 31 Gen 4 OEM Slide – $149.99+

The Glock 31 Gen 4 OEM Slide is the factory-spec slide for Glock’s full-size .357 SIG pistol — the cartridge engineered specifically for law enforcement barrier penetration and duty-grade terminal performance. Built to the dimensions of the Gen 4 large-frame platform, this slide delivers the dual recoil spring compatibility, hardened steel construction, and precise fitment required for reliable function with the high-pressure .357 SIG cartridge. Available as a stripped slide shell or a complete assembly starting from $149.99.

Built for the .357 SIG Duty Platform

The .357 SIG cartridge was developed in the 1990s specifically for law enforcement — its necked-down .40 S&W case pushing a 9mm bullet delivers rifle-like velocities, flat trajectory at distance, and reliable barrier penetration through auto glass, sheet metal, and heavy clothing. The Glock 31 Gen 4 OEM Slide is machined and heat-treated specifically for the pressures and recoil of that cartridge. Whether you’re running department-issued duty ammunition or match-grade loads, this slide holds up.

Full-Size Duty-Grade Platform

The G31 is a full-size duty pistol — same dimensions as the G17 (9mm) and G22 (.40 S&W). It gives you a 4.49-inch barrel, a full-size grip with 17-round flush magazine capacity, and the extended sight radius that duty use demands. This slide maintains all of those dimensions with factory-correct Gen 4 geometry.

Built Around Gen 4 Engineering

The Gen 4 dual recoil spring assembly is the defining mechanical advancement of that generation. It reduces felt recoil, distributes wear more evenly across components, and extends the service life of both slide and frame. This slide is dimensioned specifically for the Gen 4 dual spring — ensuring smooth cycling, controlled return-to-battery, and long-term reliability with the components you already have.

Key Features and Benefits

Generation-Matched Fit for Glock 31 Gen 4 Frames

Engineered specifically to the dimensional specs of Glock 31 Gen 4 frames. The Gen 4-specific recoil spring channel ensures perfect mating with the Gen 4 dual recoil spring assembly. No fitment gaps, no function compromises, no compatibility concerns that plague cross-generation or aftermarket alternatives.

Breech Face Machined for .357 SIG

The .357 SIG uses a .40-caliber case head (necked down to 9mm bullet diameter). This slide’s breech face is dimensioned specifically for the .357 SIG — the extractor, firing pin channel, and case-head clearances are all correct for the cartridge. It is not a 9mm slide with a different barrel; it’s a slide built for the caliber.

Standard Iron Sights Configuration

Factory-style iron sights installed and ready to use. No optic cut means a cleaner top profile and a slightly lower overall height — some duty shooters prefer iron sights for simplicity and reliability in the field.

Hardened Steel Construction for High-Pressure Cartridges

.357 SIG operates at significantly higher pressures than 9mm or .40 S&W. This slide is machined from hardened steel and heat-treated to handle those pressures over thousands of rounds without deformation, cracking, or premature wear.

Gen 4 Rear Serrations for Positive Manipulation

The Gen 4 rear serration pattern provides reliable slide manipulation under all conditions. The serration geometry is optimized for the Gen 4 grip angle and manual of arms. Fast and positive racking stays consistent whether your hands are wet, gloved, or under physical stress.

Full Magazine Compatibility

The G31 accepts G31 (.357 SIG, 15-round flush), G22 (.40 S&W, 15-round), and G17 (9mm, 17-round with aftermarket conversion barrel) magazines. For .357 SIG, always use G31 or G22 magazines with .357 SIG ammunition.

Complete Technical Specifications

Specification	Detail
Model	Glock 31 Gen 4 OEM Slide
Platform	Glock 31 (Full-Size)
Generation	Gen 4
Caliber	.357 SIG
Slide Material	Hardened Steel
Finish	Black Corrosion-Resistant Coating
Slide Length	7.32 inches
Barrel Length	4.49 inches
Front Serrations	No (standard Gen 4)
Rear Serrations	Yes (Gen 4 pattern)
Recoil System	Gen 4 Dual Captive Spring Assembly
Optic Ready	No — standard iron sights configuration
Included Sights	Factory Standard Height
Compatible Frames	Glock 31 Gen 4 and Glock 22 Gen 4
Weight (Complete)	Approximately 14.7 ounces
Configuration	Stripped or Complete

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Available Configurations

Complete Glock 31 Gen 4 OEM Slide Assembly – $249.99

Ready to install and shoot. Everything needed for a complete .357 SIG duty upper:

• Glock 31 Gen 4 Slide Shell — black finish with Gen 4 rear serrations
• Factory .357 SIG Barrel — 4.49-inch with proper chamber and throat
• Gen 4 Dual Captive Recoil Spring Assembly
• Complete Internals — striker assembly, extractor, safety plunger
• Factory Steel Sights — standard configuration
• Slide Back Plate — standard Glock polymer

Stripped Glock 31 Gen 4 OEM Slide – $149.99

For custom builders supplying their own internals and barrel:

• Glock 31 Gen 4 Slide Shell — black finish with Gen 4 rear serrations
• Factory Front and Rear Sights — standard configuration
• Channel Liner — pre-installed

Note: Does not include barrel, Gen 4 dual recoil spring assembly, or internal components. Always pair with Gen 4-specific components — Gen 5 recoil assemblies are not compatible.

Ideal For These Applications

Law Enforcement and Duty Use

The .357 SIG was engineered specifically for law enforcement — barrier penetration, consistent terminal performance through intermediate barriers, and flat trajectory at distance. The Glock 31 Gen 4 OEM Slide delivers factory-grade reliability for duty use, whether you’re running a department-issued platform or a personal duty setup.

Highway Patrol and Tactical Applications

Several state highway patrol agencies adopted the .357 SIG platform for its barrier-penetration performance against vehicles. The G31 remains a popular choice for shooters who need reliable performance through auto glass and sheet metal. This slide maintains the factory-grade reliability that tactical and patrol use demands.

Hunting and Backcountry Defense

.357 SIG has a following among hunters and backcountry users who want barrier penetration and flat trajectory at distance. The G31 is one of the more capable .357 SIG pistols available — this slide maintains that capability with factory-correct engineering.

Competition Shooting

In USPSA Limited division, the G31 can be competitive — particularly with handloaded .357 SIG ammunition tuned for major power factor. The full-size platform provides the capacity and controllability that competition shooters need.

Slide Replacement and Factory Restoration

Whether your existing G31 Gen 4 slide has sustained damage or significant wear, this slide is a direct replacement that restores factory function. Ideal for high-round-count duty pistols and legacy agency guns.

Custom .357 SIG Builds

The G31 platform offers a foundation for custom .357 SIG builds — combined with aftermarket barrels, upgraded recoil systems, and premium sights. Factory-spec construction ensures a reliable base for customization.

Fit and Compatibility

What This Slide Is Compatible With

• Glock 31 Gen 4 frames (all variations)
• Glock 22 Gen 4 frames — with a .357 SIG barrel, this slide converts a G22 to .357 SIG
• Gen 4 dual recoil spring assemblies (.357 SIG rated)
• Gen 4 specific .357 SIG barrels
• Gen 4 specific internals
• G31 (.357 SIG) and G22 (.40 S&W) magazines

What This Slide Is NOT Compatible With

• Glock 31 Gen 3 or Gen 5 frames — different recoil spring geometry
• 9mm frames (G17, G19, G26) — different breech face dimensions
• Glock 32 or G33 frames — different slide dimensions (compact and subcompact)
• .40 S&W frames without a matching barrel change
• Gen 5 recoil spring assemblies — not dimensionally compatible with Gen 4 slides

Critical Caliber Compatibility Note

The .357 SIG uses a necked-down .40 S&W case, which means it shares the .40-caliber case head dimensions. This is why the Glock 31 slide can fit a Glock 22 frame — but it must use a .357 SIG barrel and .357 SIG magazines. Do not attempt to fire .40 S&W ammunition in a .357 SIG barrel or vice versa — the cartridges are not interchangeable even though they share a case head.

Holster Compatibility

Holsters designed for the Glock 17, Glock 22, or Glock 31 Gen 4 fit this slide perfectly. The exterior dimensions are identical across these full-size platforms. Standard G17/G22/G31 holsters work without modification.

Care and Maintenance Guide

Finish Care

Clean with a quality solvent and soft cloth after every range session. The corrosion-resistant finish holds up well under heavy use. Avoid abrasive cleaners or metal polishes that can damage the surface.

Gen 4 Dual Recoil Spring Inspection

The Gen 4 dual recoil spring assembly works harder in .357 SIG than in lighter calibers. Inspect it at every cleaning and replace it every 3,000–5,000 rounds to maintain consistent cycling and reliability.

Barrel and Chamber Care

The .357 SIG operates at very high pressures. Clean the chamber and bore thoroughly after every session. Inspect the chamber for signs of pressure-related wear at regular intervals — particularly if you run high-volume duty ammunition.

Extractor Inspection

Because .357 SIG operates at high pressure, the extractor works harder than in lower-pressure calibers. Inspect the extractor claw periodically for wear and replace it if you notice inconsistent ejection or extraction issues.

Striker Channel Cleaning

Regularly clean the striker channel to prevent primer residue buildup. A clean striker channel ensures consistent ignition across all ammunition types and temperatures.

Rail Lubrication

Apply quality firearm lubricant to slide rails after each cleaning. The .357 SIG’s sharp recoil impulse makes smooth operation more important than in lighter calibers.

Frequently Asked Questions

About the .357 SIG Platform

Q: What makes .357 SIG different from other handgun cartridges? A: The .357 SIG is a necked-down .40 S&W case firing a 9mm bullet. It delivers significantly higher velocity and flatter trajectory than standard 9mm, with barrier-penetration performance comparable to magnum revolver cartridges. Q: What’s the difference between the Glock 31, 32, and 33? A: The G31 is the full-size .357 SIG (G17-length). The G32 is the compact version (G19-length). The G33 is the subcompact version (G26-length). They share the caliber but not the slide dimensions. Q: Can I convert my Glock 22 (.40 S&W) to .357 SIG with this slide? A: Yes. The G31 and G22 share frame and slide dimensions. With this slide, a .357 SIG barrel, and .357 SIG magazines, you can convert a G22 Gen 4 frame to .357 SIG. Do not fire .40 S&W ammunition in a .357 SIG barrel — the cartridges are not interchangeable.

Fit and Function

Q: Will this slide fit a Gen 3 or Gen 5 Glock 31 frame? A: No. Gen 4 slides require Gen 4 frames due to the different dual recoil spring system. Gen 3 uses a single recoil spring; Gen 5 uses a different locking block geometry. Q: Can I run a .40 S&W barrel in this slide? A: Yes, physically — .40 S&W and .357 SIG share the same case head dimensions. However, you must use .40 S&W magazines and be aware that .357 SIG magazines may not feed .40 S&W reliably. Always verify function before relying on a caliber conversion. Q: What recoil spring weight does this slide require? A: The Gen 4 dual captive recoil spring assembly is required. Use a .357 SIG-rated spring. Standard 9mm recoil springs are not compatible.

Technical Information

Q: Is the .357 SIG cartridge hard on slides? A: Yes. .357 SIG operates at significantly higher pressures than 9mm or .40 S&W. This slide is machined from hardened steel and heat-treated specifically for those demands. Q: Can this slide be milled for an optic? A: Yes, many gunsmiths offer slide milling for common optic footprints. Milling will void the original finish warranty, but it does not compromise the structural integrity of this slide. Q: What is the difference between the stripped and complete versions? A: The complete assembly ($249.99) includes the factory barrel, Gen 4 dual recoil spring assembly, all internal components, and factory sights — ready to install. The stripped slide ($149.99) includes only the slide body, sights, and channel liner. Internals must be sourced separately. Q: Does the G31 share magazines with the G22? A: Yes. The G31 and G22 use the same magazine body. G22 .40 S&W magazines function in the G31 platform, but for reliable .357 SIG feeding, use factory G31 magazines when possible.

Ordering and Support

Q: What payment methods do you accept? A: We accept all major credit cards, PayPal, and Apple Pay for secure checkout. Q: Do you offer a law enforcement or military discount? A: Yes. Verified law enforcement, military, and EMS personnel receive a discount. Contact us before ordering to verify eligibility. Q: How long does shipping take? A: Most orders ship within 2–3 business days. Continental US delivery typically takes 3–5 business days after shipping. International orders usually arrive in 7–14 business days after shipping.

Why Choose the Glock 31 Gen 4 OEM Slide

Built for the .357 SIG Platform

.357 SIG is a duty-focused caliber with a dedicated following. This slide is machined specifically for the platform — not adapted from a 9mm slide. Every dimension matches what the .357 SIG cartridge requires.

Factory-Spec Reliability for Duty Use

For law enforcement and defensive carry use, factory-spec components ensure complete reliability. The G31’s service record confirms the platform’s dependability under sustained operational conditions.

Glock 22 Frame Cross-Compatibility

The G31 slide shares dimensions with the G22, which means this slide can convert a G22 Gen 4 frame to .357 SIG. That gives Glock 22 owners a factory-spec path to .357 SIG capability without buying a separate pistol.

Full Parts Interchangeability

Maintains complete interchangeability with OEM Gen 4 components and factory service parts. Armorers and professional users can service and maintain it with confidence.

Add to Cart Options

– Complete Glock 31 Gen 4 OEM Slide Assembly – $249.99 – Stripped Glock 31 Gen 4 OEM Slide – $149.99 📦 Free Shipping on Orders Over $300 🔒 Secure SSL Checkout ⚡ Ships Within 2–3 Business Days Related Products: Glock 32 Gen 4 OEM Slide – Compact .357 SIG slide Glock 22 Gen 5 MOS OEM Slide – Full-size .40 S&W optics-ready Glock 23 Gen 5 OEM Slide – Compact .40 S&W slide Shop All Duty & Full-Size Slides Explore Related: Glock 31 Slides · Glock 32 Slides · Glock 22 Slides · All Glock Slides For official Glock maintenance and armorer guidance, see Glock’s official resource page.