Magpul UBR Gen2 Collapsible Stock - Flat Dark Earth Synthetic for AR-15/M16/M4

The Magpul UBR Gen2 collapsible stock for AR-15, M16, and M4 platforms brings precision adjustability to your rifle without compromising stability. Where many shooters settle for a fixed position, the UBR Gen2 delivers eight different length-of-pull positions—each with a fixed cheek piece that maintains a consistent, repeatable cheek weld. That consistency matters at distance and in unpredictable field conditions: your sight picture stays the same whether you're in full extension or fully collapsed. Built lighter than the original UBR while retaining the same legendary durability, this stock is engineered to handle high-round-count sessions and severe impacts without flex or rattle.

The UBR Gen2 works with standard carbine-length buffer systems and is also compatible with A5 and SR-25 length systems, making it adaptable across different AR builds and configurations. The included custom receiver extension tube is designed for rigidity and precise positioning across all eight detents. You get two sling attachment points (front and rear QD loops), two footman's loops for gear attachment, and a customizable storage compartment built into the buttstock—practical features that make this stock do more than just adjust length. The MOE SL rubber butt-pad offers genuine ergonomic shaping and impulse absorption.

Built in the U.S.A. from synthetic materials proven in duty and competition use, the Flat Dark Earth finish is a professional middle ground—neutral enough for any mission, distinctive enough to stand out in a safe. Whether you're building a precision rifle, reconfiguring a duty AR, or just want the flexibility to fit different shooters and clothing layers, the UBR Gen2 is a no-compromise adjustable option.

Key Features

• Eight positions of adjustment with fixed cheek piece for consistent cheek weld at every length
• Compatible with carbine, A5, and SR-25 length buffer systems
• Custom receiver extension tube included for secure, precise mounting
• Front and rear QD sling attachment points
• Two footman's loops for accessory attachment
• Customizable storage compartment integrated into buttstock
• MOE SL angled-toe rubber butt-pad for comfort and recoil control
• Enhanced lock mechanism for reliability across positions
• Lighter than original UBR while maintaining legendary durability
• Made in U.S.A.

Specifications

Frequently Asked Questions

Is the UBR Gen2 compatible with my AR-15 or M4?

Yes. The UBR Gen2 is designed for AR-15, M16, and M4 platforms and works with standard carbine-length buffer systems as well as A5 and SR-25 length systems. The custom receiver extension tube is included, so installation is straightforward.

What makes the cheek weld consistent across all eight positions?

The UBR Gen2 features a fixed cheek piece that remains in the same position regardless of which of the eight length-of-pull settings you select. This means your sight picture and shooting geometry stay consistent whether the stock is extended or collapsed.

What's included in the box?

The stock comes with the custom receiver extension tube, front and rear QD sling attachment points, two footman's loops, the MOE SL rubber butt-pad, and a customizable storage compartment built into the buttstock.

How does this stock compare to the original UBR?

The UBR Gen2 is approximately five ounces lighter than its predecessor while retaining the same durability and strength. It features the same multi-position adjustability with the added benefit of the fixed cheek piece for consistent cheek weld and an enhanced lock mechanism.