The Magpul STR stock is a collapsible carbine buttstock for AR-pattern rifles that mounts on mil-spec sized carbine receiver extension tubes. It combines wobble reduction with dual battery storage and a sloping cheek weld for field use.
This stock addresses two common complaints about standard carbine stocks: unwanted play between the stock and the buffer tube, and the lack of onboard battery storage for weapon lights and optics.
The grey finish offers a neutral color option for shooters building rifles with non-black furniture or mixing Magpul components across multiple tones.
Key Facts
Compatibility: Mounts on mil-spec sized carbine receiver extension tube from manufacturers such as Colt, Armalite, S&W, LMT, and others
Battery Storage: Two water-resistant storage tubes located on left and right sides, accessible from the rear in any stock position via hand-removable rubber plug
Wobble Reduction: Supplemental friction lock minimizes stock-to-tube play
QD Compatibility: Reversible Type 1 sling mount fits push-button QD swivels up to 1.5 inches
Standard carbine stocks often develop side-to-side or vertical movement where the stock slides onto the buffer tube. That play grows with use and degrades cheek weld consistency.
The Magpul STR buttstock uses a supplemental friction lock to tighten the fit between stock and tube. The lock applies pressure at a second contact point beyond the standard locking detent. A premium chrome-silicon lock spring provides positive locking and maintains tension over time.
The shielded release latch prevents snagging on gear or vegetation and resists accidental operation during manipulation.
Battery Storage for Lights and Optics
Many AR users mount weapon lights, red dots, or magnified optics that require battery power. The STR stock provides two water-resistant battery storage tubes, one on each side of the stock body.
Both tubes are accessible from the rear via a hand-removable rubber plug. You can access the batteries in any stock position without collapsing or extending the stock. This matters when you need to swap a battery during a class or in low light.
For battery capacity and compatible sizes, send us a message to confirm compatibility with your specific cells.
STR Stock vs MOE and CTR Stocks
The Magpul product line includes several carbine stocks. The MOE stock is the basic model with a friction lock. The CTR stock adds a lever lock for tighter lockup. The STR buttstock combines the friction lock system with dual battery tubes and a wider cheek weld surface.
Shooters who need onboard battery storage typically choose the STR. Shooters who want the tightest possible lockup without battery storage often prefer the CTR. Both use the same sloping cheek weld geometry for consistent head position.
Browse our full selection of grips, pads, and stocks for other Magpul and aftermarket options.
Compatibility with Mil-Spec Buffer Tubes
The Magpul STR mounts on mil-spec carbine receiver extension tubes, not commercial-spec tubes. Mil-spec tubes measure approximately 1.14 inches in outer diameter. Commercial tubes measure slightly larger and will not fit this stock.
Most quality AR manufacturers use mil-spec dimensions.
The stock is compatible with Magpul ASAP and other receiver-mount sling attachments. The rear sling mount is reversible for left- or right-side placement. A 1.25-inch sling loop is located at the rear bottom.
Ordering from Western Sport
Order online and it ships straight to your door. Western Sport has been a licensed FFL/SOT dealer since 2007, and everything we sell carries the full manufacturer warranty. Questions before you order? Send us a message.
Frequently Asked Questions
Q: Does the Magpul STR stock fit commercial buffer tubes?
A: No, the Magpul STR stock mounts only on mil-spec sized carbine receiver extension tubes from manufacturers such as Colt, Armalite, S&W, and LMT. Commercial-spec tubes have a larger diameter and are not compatible. Send us a message if you need help identifying your buffer tube type.
Q: How does the STR stock friction lock work?
A: The supplemental friction lock on the STR buttstock applies pressure at a second contact point beyond the standard locking detent to reduce wobble between the stock and buffer tube. The chrome-silicon lock spring maintains positive locking pressure and resists wear over repeated adjustments.
Q: Can I access the battery storage tubes when the stock is collapsed?
A: Yes, the water-resistant battery storage tubes are accessible from the rear in any stock position via hand-removable rubber plugs. You do not need to extend or adjust the stock to reach the batteries.
Q: What is the difference between the Magpul STR and CTR stocks?
A: The Magpul STR stock features dual battery storage tubes and a friction lock, while the CTR stock uses a lever lock for tighter lockup but does not offer battery storage. Both provide wobble reduction and a sloping cheek weld, but the STR is designed for shooters who need onboard battery storage for lights and optics.
Q: Will the STR stock work with QD sling mounts?
A: Yes, the reversible Type 1 sling mount on the rear of the STR stock fits push-button QD swivels up to 1.5 inches. The stock also features a 1.25-inch sling loop at the rear bottom for traditional sling attachment.
Additional information
Weight
2 lbs
Features
Mounts on mil-spec sized carbine receiver extension tube (not included) from manufacturers such as Colt, Armalite, S&W, LMT, and others (please see the note below) Two water-resistant battery storage tubes located on the left and right sides of the stock Each tube will store up to two (2) CR123A lithium or AA batteries Tubes are accessible from the rear in any stock position via a hand-removable rubber plug Supplemental friction lock minimizes accuracy robbing wobble* Premium chrome-silicon lock spring provides positive locking and long service life Sloping cheek weld provides a wide contact surface for user comfort Shielded release latch prevents snagging and accidental operation Replaceable 0.30" Rubber Butt-Pad offers an anti-slip surface and increases impact protection Compatible with Magpul ASAP® and other receiver-mount sling attachments Sling Mounts Rear – Reversible Type 1 Sling Mount fits up to 1.5" push-button QD swivels (swivel not included) Rear/Bottom – 1.25" sling loops
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