The Magpul UBR GEN2 is a collapsible rifle stock for AR-15/M4 and AR-10/SR25 rifles, supplied as a complete system with its own receiver extension.
The Magpul UBR GEN2 (MAG482) — Utility/Battle Rifle — solves the collapsible stock's oldest flaw. Its cheek weld riser stays fixed relative to your face while the butt extends and retracts beneath it, so every length-of-pull setting delivers exactly the same head position and sight picture. Combined with a chassis engineered to near-zero play, the UBR gives hard-recoiling AR-10/SR25 builds and service AR-15s a stock with genuine fixed-stock integrity.
Storage is built into the butt, the rubber pad plants firmly, and the structure tolerates abuse — buttstrokes included — that would destroy lighter designs. It is the heaviest-service collapsible stock Magpul makes, and it feels like it.
Key Features
- Constant cheek weld riser: identical head position at every length
- Near-zero play chassis: fixed-stock rigidity, collapsible convenience
- Fits AR-15/M4 and AR-10/SR25: built for big-bore recoil
- Integral storage compartment: essentials sealed onboard
- Four finishes: Black, Flat Dark Earth, Olive Drab Green, Stealth Gray
Compatibility & Fitment
Fits AR-15/M4 and AR-10/SR25 pattern rifles. It is supplied as a complete stock system with its own receiver extension, so it installs in place of your existing buffer tube assembly rather than sliding onto it — check Magpul's documentation for buffer and spring compatibility on your build. Allow a little more bench time than a slide-on stock; the result justifies it.
Technical Specifications
Platform | AR-15/M4 & AR-10/SR25 |
Fits | Supplied with its own receiver extension |
Type | Collapsible stock with constant cheek weld |
Material | Polymer & aluminum |
Finish | Black, Flat Dark Earth, Olive Drab Green, Stealth Gray |
US Shipping & Support
Shipped from D&R Sports Center in the USA with fast, tracked delivery. Questions on fit, mounting or which model suits your setup? Our team is glad to help before and after your purchase.
Frequently Asked Questions
What rifles does the UBR GEN2 fit?
It's made for AR-15/M4 and AR-10/SR25 pattern rifles and is supplied as a complete stock system rather than a stock alone. Because it's a system, buffer and spring compatibility matters, so check Magpul's documentation for your build before you buy. If you're working from an existing rifle rather than a fresh build, contact us with the details and we'll go through it.
What is a constant cheek weld and why does it matter?
On most collapsible stocks the comb moves with the stock, so your cheek position changes as you shorten or extend the length of pull. The UBR GEN2 keeps the cheek piece in the same place while the length adjusts around it, so your eye stays at the same height relative to the sights. That's worth having if you shoot in body armor or heavy clothing and need to change length often.
How is it built?
It uses a combination of polymer and aluminum, which is why it feels more substantial than a plain polymer carbine stock. That construction is aimed at rigidity, so the stock resists flex when it's loaded against the shoulder or used to steady the rifle. It sits at the heavier end of the range as a result.
Which color, and who is it for?
Black, Flat Dark Earth, Olive Drab Green and Stealth Gray are offered. It's the choice for someone who wants the sturdiest collapsible option and is willing to accept the weight and the system-level fitting; if you want light and simple, look at the lighter carbine stocks.
