AR15 M16 Replacement CTR Carbine Butt Stock Commercial - Black - Magpul


Item #: MPMAG311


In Stock for Immediate Shipping

Manufacturer MPN:
Magpul MAG311

UPC: 873750001548
Weight: 0.57 pounds

Product Description

CTR Carbine Stock – Commercial-Spec

Made in the USA

Platform: AR10, AR15, M4, M16, M110, SR25
Compatibility: Com-Spec sized carbine receiver extension tube (not included) from manufacturers such as Bushmaster, DPMS, and others.
LOP, M4 Collapsed ~ 10.8”
LOP, M4 Extended ~ 14.6”
LOP Adjustment Range: 3.8”
Length, Max: 7.2”
Weight: 9.3 oz.
Weight, Stock Body: 0.57 lb.
Weight, w/ Receiver Extension: 13.6 oz.

Iconic AR Stock
Secure “Set it and Forget it” Fit
The Right Balance of Cheek Weld and Comfort
Dependable Adjustability
Sling Point Variety
Impact Mitigation

The Magpul CTR (Compact / Type Restricted - Commercial Model) is a drop-in replacement butt stock for carbines using commercial receiver extension tubes. Designed for light, fast action the streamlined A-frame profile avoids snagging and shields the release latch to prevent accidental activation. The extra-power lock mechanism uses a premium chrome-silicon spring to avert auto-collapse failure and maintains strength by resisting spring relaxation.

The CTR also features a supplemental friction lock system that eliminates wobble for enhanced weapon stability and accuracy. The Commercial Model includes an extended 0.55" rubber butt-pad to provide positive shoulder purchase and accommodates longer slant-back extension tubes. 

Mounts on Commercial-Spec Carbine Receiver Extension tube (Not included). Shielded release latch prevents snagging and accidental operation while the supplemental friction lock minimizes accuracy-robbing wobble.

Sloping cheek weld combines a slim profile with user comfort. Side mounting slots accept optional cheek risers for NON-AR15 / M16 applications. Premium chrome-silicon lock spring provides positive locking and long life.

Compatible with Magpul ASAP, ASAP QD, and other receiver-mount sling attachments. Removable 0.55” Extended Rubber Butt-Pad offers an anti-slip surface and increases impact protection.

Sling Mounts

Rear - Push-button QD sling mounts accommodate up to 1.5" swivels (Ambidextrous)

Rear / Bottom - 1.25" Sling loops

Toe - Lanyard hole for custom para-cord rigs


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 CTR.

Specifications based on extended-length (slant-back) M4 Carbine Receiver Extension may vary depending on tube specifications.

Friction lock performance may vary depending on the receiver extension's dimensional tolerances.


This item or some of its components cannot be exported from the United States of America without a valid export permit from the U.S. State Dept. Unfortunately, this also includes APO addresses due to ITAR restrictions.

CTR Stock Install Instructions

Step 1:  Remove Existing Stock
Remove existing stock per armory guidelines. Refer to 
US Army TM 9-1005-319-23&P for assistance.

Step 2: Install CTR Stock

DO NOT FORCE PARTS TOGETHER!! Align the stock body with the carbine receiver extension and gently slide together until the stock stops (approx. 2-1/8”). Depress release latch with one hand. With the other hand, grasp both ends of release pin and pull down firmly. Push stock forward to mount.

NOTE: If stock does not easily slide over receiver extension, refer to fit guide on box.

Step 3: Friction Lock Test
With the stock installed and secured in position, depress the friction lock to minimize movement.

NOTE: Friction Lock performance may vary depending on exact receiver extension size.

Step 4: Verify Install

Perform final inspection including function test per US Army TM 9-1005-319-23&P Unit and Direct Support Maintenance Manual to verify correct installation. If you experience any issues during installation, please refer to the “Related Info” tab, located on the product page at Always test fire your weapon before using it in an operational environment.

Removing CTR Stock
Depress release latch with one hand. With the other hand grasp both ends of the release pin and pull down firmly. Pull the stock body clear of the carbine receiver extension.

CTR Stock Adjustment Instructions
Extend/Collapse Stock

Fully depress the release latch and pull the stock rearward to extend or push stock forward to collapse. Intermediate positions may be selected by depressing the release latch and moving the stock back to the desired position. When desired position is found re-engage friction lock bolt for best results.

Remove Rubber Butt Pad
Use a 1/8” hex key to remove the two butt pad screws. Using a bullet tip or flat head screwdriver, depress the two top snap hooks to release the pad. Install optional polymer Carbine Butt Cap if desired.

WARNING: The CTR commercial model has an extended .55” rubber butt pad to accommodate extended-length receiver extensions (buffer tubes). Removal of the butt pad is not recommended since the extension tube may protrude past the end of the stock in the fully collapsed position and may cause discomfort or injury during use.

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