Dual, rear accessible, water-resistant battery storage tubes and an integral storage compartment in the butt of the stock provides multiple storage options.

 
The patented Magpul ACS (Adaptable Carbine/Storage) – Mil-Spec or Commercial Model is a drop-in replacement buttstock for AR15/M16 carbines using commercial-spec sized receiver extension tubes. A streamlined, anti-snag profile shields the release latch to prevent accidental activation. Similar to the Magpul CTR®, the ACS also features a supplemental friction lock system that minimizes excessive stock movement for enhanced weapon stability and accuracy*. Dual, rear accessible, water-resistant battery storage tubes and an integral storage compartment in the butt of the stock provides multiple storage options. The ACS comes standard with a 0.30" thick rubber butt-pad which provides positive shoulder purchase to prevent slippage even with body armor or modular gear.
 
Made in USA
 
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)
• Sloping cheek weld provides a wide contact surface for user comfort
• Two water-resistant battery storage tubes located on the left and right sides of the stock
• Each tube will store up to three CR123 lithium or two AA batteries
• Tubes are accessible from the rear via a tethered, hand-removable rubber plug
• Storage compartment in tail of stock with positive latching access door on right hand side
• Supplemental friction lock minimizes accuracy robbing wobble*
• Shielded release latch prevents snagging and accidental operation
• Premium chrome-silicon lock spring provides positive locking and long service life
• 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
• Mid - Now includes the QD Swivel Sling Mount that fits up to 1.5" push-button swivels
• Rear/Bottom - 1.00" sling loop

 
Optional Accessories**

• Extended Rubber Butt-Pad, 0.55"
• Enhanced Rubber Butt-Pad, 0.70"

 
Specifications**

• ACS, Commercial-Spec (stock configuration)
• Weight: 0.88 lb.
• Weight, w/ Rec. Extension: 1.22 lb.
• Length, Maximum: 7.95 in.
• Width, Maximum: 2.58 in.
• LOP Adjustment Range: 3.80 in.
• LOP, M4 Collapsed: 11.75 in.
• LOP, M4 Extended: 15.55 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 ACS. 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 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 ACS stocks.