Magpul STR – Carbine Stock Mil-Spec Model (Black)

Product Description

The Magpul STR Carbine Stock Mil-Spec Model is a drop-in buttstock designed for AR-15 and AR-10 pattern rifles with mil-spec sized carbine receiver extension tubes. It mounts on standard mil-spec buffer tubes from manufacturers such as Colt, Armalite, S&W, and LMT.

The STR stock addresses two common complaints about standard carbine stocks: buffer tube wobble and lack of onboard storage. A supplemental friction lock minimizes the play between stock and tube that can affect accuracy. Two water-resistant battery storage tubes are built into the left and right sides of the stock body.

Each storage tube is accessible from the rear in any stock position via a hand-removable rubber plug. The design provides quick access to spare batteries without tools, even when the stock is fully collapsed or extended.

Key Facts

• Compatibility: Mil-spec sized carbine receiver extension tubes from Colt, Armalite, S&W, LMT, and similar manufacturers
• Battery Storage: Two water-resistant tubes, each accessible via hand-removable rubber plug from the rear
• Friction Lock: Supplemental lock minimizes wobble between stock and buffer tube
• Sling Attachment: Reversible QD swivel mount fits up to 1.5″ push-button swivels, plus 1.25″ sling loops
• Finish: Black
• SKU: MAG470-BK

How the STR Stock Differs from Standard Carbine Stocks

Most mil-spec carbine stocks rely solely on the buffer tube detent positions to lock the stock in place. Over time or with manufacturing tolerance stacking, this creates side-to-side and up-down movement. The STR stock adds a friction lock that applies pressure against the buffer tube to reduce that wobble.

The lock uses a premium chrome-silicon spring for positive engagement and long service life. You tighten or loosen the friction lock with a flathead screwdriver or similar tool. This feature is particularly useful for shooters who notice accuracy shifts when cheek weld pressure changes the stock angle on a loose buffer tube.

The sloping cheek weld design provides a wide contact surface. The replaceable 0.30″ rubber butt-pad offers an anti-slip surface and increases impact protection against the shoulder.

Fit and Compatibility Notes

The STR stock fits mil-spec carbine receiver extension tubes only. Mil-spec tubes measure approximately 1.14 inches in outside diameter. Commercial-spec tubes are slightly larger and will not fit this stock.

The stock is compatible with Magpul ASAP and other receiver-mount sling attachments. The shielded release latch prevents snagging on gear and reduces the chance of accidental stock position changes during weapon manipulation.

If you are unsure whether your buffer tube is mil-spec or commercial-spec, send us a message before ordering. Our gunsmith can confirm fitment for your specific rifle.

Magpul STR Weight and Battery Tube Capacity

Battery tube capacity is specified by the manufacturer, but overall weight of the STR stock is not provided in the technical data. Send us a message if you need weight confirmation for a specific build or competition requirement.

The battery tubes are designed as field-accessible storage for electronics commonly used on defensive and duty rifles. The tubes are sealed with rubber plugs to keep moisture out during transport and storage.

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-spec buffer tubes?

A: No, the STR stock mounts only on mil-spec sized carbine receiver extension tubes. Commercial-spec tubes are larger in diameter and will not fit. Mil-spec tubes are used by Colt, Armalite, S&W, LMT, and most other manufacturers, but confirm your tube diameter before ordering.

Q: How does the friction lock on the STR stock work?

A: The friction lock applies adjustable pressure against the buffer tube to reduce wobble and play between the stock and tube. You adjust tension with a flathead screwdriver or similar tool. The lock uses a chrome-silicon spring for consistent performance over time.

Q: What is the difference between the Magpul STR and MOE stock?

A: The STR stock adds a friction lock system and dual battery storage tubes that the MOE stock does not have. The STR also features a sloping cheek weld and replaceable rubber butt-pad. The MOE stock is lighter and simpler with no onboard storage or friction adjustment.

Q: Can I use QD sling swivels with the STR stock?

A: Yes, the STR stock has a reversible QD swivel sling mount at the rear that fits push-button swivels up to 1.5 inches. There are also 1.25-inch sling loops at the rear and bottom of the stock. The QD swivel itself is not part of the stock.

Q: Is the Magpul STR buttstock available in colors other than black?

A: This model, SKU MAG470-BK, is black. Magpul manufactures the STR stock in several colors, but availability varies. Send us a message to ask about other color options or special orders.

Q: How do I install the STR stock on my AR-15?

A: Depress the buffer retainer pin, slide the STR stock onto the mil-spec buffer tube from the rear, and release the pin when the stock reaches your desired position. Adjust the friction lock screw to eliminate wobble.

Additional information