FAB Defense GL-CORE AR-15/M4 Collapsible Stock

FAB Defense GL-CORE AR-15/M4 Collapsible Stock

The FAB Defense GL-CORE is a collapsible stock designed for AR-15, M4, and other compatible platforms using a carbine-style receiver extension. It combines adjustable length of pull with a broad cheek-weld surface, rubberized buttpad, and a dual-tube fitment system that allows the stock to be configured for both MIL-SPEC and commercial-pattern receiver extensions.

The GL-CORE is the standard model in FAB Defense's GL-CORE stock family. Compared with the shorter GL-CORE S or the cheek-rest-equipped GL-CORE CP, this version uses a conventional collapsible-stock profile without an added adjustable cheek piece, making it a straightforward option for general-purpose AR-pattern rifles and carbines.

Key Features

• Designed for AR-15, M4, and compatible platforms
• Collapsible stock with adjustable length of pull
• Fits MIL-SPEC and commercial-pattern carbine receiver extensions
• Interchangeable tube adapters for proper fit
• Broad cheek-weld surfaces
• Rubberized buttpad for secure shoulder contact
• Inverted adjustment lever helps reduce accidental activation
• Integrated sling attachment provisions
• Reinforced polymer construction
• Available in Black, OD Green, and Flat Dark Earth

Dual Receiver Extension Compatibility

One of the GL-CORE's primary advantages is compatibility with both common carbine receiver-extension specifications. FAB Defense uses interchangeable adapters to fit MIL-SPEC and commercial-pattern tubes, allowing the same stock body to be configured around either tube diameter.

This eliminates the need to purchase separate MIL-SPEC and commercial versions of the stock. Buyers should identify the receiver extension installed on their firearm and use the appropriate adapter for proper fit.

Adjustable Carbine Stock Design

The GL-CORE moves along the receiver extension to provide multiple length-of-pull positions. This allows the rifle to be adjusted for shooter size, body armor, clothing, shooting position, or storage requirements while retaining the familiar architecture of a collapsible AR stock.

The stock body provides a larger cheek-contact surface than many minimalist designs. This gives the shooter a more defined reference point for head placement without adding the height-adjustable cheek piece found on the GL-CORE CP.

Ergonomic Rear Interface

A rubberized buttpad creates a high-friction contact surface against the shoulder, while the stock's contoured sides provide support for a repeatable cheek weld. The combination is intended to provide a more substantial rear interface than a basic M4-style stock without moving into the size and adjustment range of a dedicated precision stock.

The stock-position lever is recessed and inverted beneath the body to help protect it from unintended activation during handling or movement.

Product Specifications

• Manufacturer: FAB Defense
• Model: GL-CORE
• Type: Collapsible Carbine Stock
• Primary Platform: AR-15 / M4 and Compatible Platforms
• Receiver Extension Compatibility: MIL-SPEC and Commercial Carbine Tubes
• Length of Pull: Adjustable
• Buttpad: Rubberized
• Construction: Reinforced Polymer

Color Variants

• Black: FX-GLCOREB | UPC 7290105944757
• OD Green: FX-GLCOREG | UPC 7290105945969
• Flat Dark Earth: FX-GLCORET | UPC 7290105945976

Fitment Note: The GL-CORE is designed for compatible carbine-style receiver extensions. Buyers should verify whether their firearm uses a MIL-SPEC or commercial-pattern tube and install the corresponding adapter before use.

GL-CORE Stock Family

The standard GL-CORE sits between FAB Defense's more specialized stock configurations. The GL-CORE S uses a shorter body for compact CQB-oriented rifles, while the GL-CORE CP adds an adjustable cheek rest for applications requiring additional comb height. The standard GL-CORE retains the full-size collapsible profile for buyers who want straightforward length adjustment, broad tube compatibility, and a conventional cheek-weld surface.

WARNING This product may contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, visit www.P65Warnings.ca.gov. You must be 18 or older to shop or purchase on our website, and 21 or older to purchase ammunition or firearms. Check local laws before ordering. By ordering, you certify that you meet all federal, state, and local legal requirements. There are no returns or exchanges on armor, firearms, ammunition, or PPE. Ammunition ships UPS Ground to the lower 48 states.
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