The Magpul STR (Storage/Type Restricted) Carbine Stock – Mil-Spec is a drop-in replacement buttstock for AR15/M4 carbines using Mil-Spec sized receiver extension tubes. A storage-capable version of the CTR®, the STR has improved cheek weld and two water resistant battery tubes on a compact, reinforced polymer A-frame design.

A shielded operation lever and supplemental friction locking system prevent accidental operation and minimize excessive stock movement for enhanced weapon stability and accuracy.* The STR incorporates two integral sling loops, a reversible push-button QD sling mount, and a replaceable 0.30″ thick rubber butt-pad which provides positive shoulder purchase to prevent slippage even with body armor or modular gear.

Made in the USA.

• MULTI-USE AR STOCK; 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).
• WATER-RESISTANT STORAGE; Two water-resistant battery storage tubes located on the left and right sides. 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.
• SHIELDED RELEASE LATCH; Prevents snagging and accidental operation. Supplemental friction lock minimizes accuracy-robbing wobble*.
• THE RIGHT BALANCE OF CHEEK WELD AND COMFORT; Sloping cheek weld combines a slim profile with user comfort.
• AIMPACT MITIGATION; Replaceable 0.30″ Rubber Butt-Pad offers an anti-slip surface and increases impact protection.
• LONG LASTING ADJUSTABILITY;Premium chrome-silicon lock spring provides positive locking and long service life 
• SLING POINT VARIETY; Compatible with Magpul ASAP®, ASAP® QD 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

Technical Specifications:
Platform: AR10, AR15, M4, M110, SR25
Compatibility: Mil-Spec sized carbine receiver extension tube (not included) from manufacturers such as Colt, Armalite, S&W, LMT, and others
LOP Adjustment Range: 3.3in
Length, Max: 7.3in
Weight: 12.3oz
Weight, w/ receiver extension: 16.3oz
Width, Max: 2.6in
Other Specs:
* Friction lock performance may vary depending on the host receiver extension’s dimensional tolerances.
** Specifications based on standard-length (flat-back) M4 Carbine receiver extension and may vary depending on tube manufacturer.

NOTE: There are two basic sizes of M4 Carbine receiver extensions (buffer tubes): Mil-spec and Commercial-Spec. If you have a Commercial-Spec extension on your rifle, make sure to order the Commercial-Spec STR.