The Magpul STR (Storage/Type Restricted) is a drop-in replacement buttstock for AR15/M16 carbines using commercial-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″ rubber butt-pad which provides positive shoulder purchase to prevent slippage even with body armor or modular gear.

Features

• Mounts on commercial-spec sized carbine receiver extension tube (not included) from manufacturers such as Bushmaster, DPMS, Olympic, 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

Optional Accessories**

• Extended Rubber Butt-Pad, 0.55″
• Enhanced Rubber Butt-Pad, 0.70″
• Dual-side push-button QD swivel Type 2 Sling Mount

Specifications**

• STR, Commercial-Spec (stock configuration)
  • Weight: 0.77 lb.
  • Weight, w/ Rec. Extension: 1.10 lb.
  • Length, Maximum: 7.30 in.
  • Width, Maximum: 2.58 in.
  • LOP Adjustment Range: 3.25 in.
  • LOP, M4 Collapsed: 11.10 in.
  • LOP, M4 Extended: 14.35 in.

NOTE: There are two basic sizes of M4 Carbine receiver extensions (buffer tubes): mil-spec and commercial-spec. If you have a mil-spec extension on your rifle, make sure to order the Mil-Spec STR. Please see the “Related Info” section above to determine which tube you have.

* Friction lock performance may vary depending on the host receiver extension’s dimensional tolerances.
** Specifications based on extended-length (slant-back) commercial-spec carbine receiver extension and may vary depending on tube manufacturer.
Standard Rubber Butt-Pad, 0.30″ weight: 0.08 lb. Optional Extended Rubber Butt-Pad, 0.55″ (weight: 0.11 lb.) or Enhanced Butt-Pad, 0.70″ (weight: 0.13 lb.) may be used with either Mil-Spec or Commercial-Spec STR stocks.