The Magpul CTR (Compact/Type Restricted – Military Model) is a drop-in replacement butt stock for carbines using mil-spec 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 Military Model includes a standard 0.30” rubber butt-pad which provides positive shoulder purchase to prevent slippage even with body armor or modular gear.

Note: There are two basic types of M4 Carbine Receiver Extensions (buffer tubes): Mil-Spec and Commercial. If you have a Commercial extension on your rifle, make sure to order the Commercial CTR (MPMAG311). If you have one of the uncommon military tubes with an extended slant-back, please contact Magpul for an Extended 0.55” Rubber Butt-Pad (sold separately).  Made in the USA.

Features 

Mounts on Military Carbine Receiver Extension tube (Not included)

Premium chrome-silicon lock spring provides positive locking and long service life

Supplemental friction lock eliminates accuracy robbing wobble

Sloping cheek weld combines a slim profile with user comfort

Shielded release latch prevents snagging and accidental operation

Side mounting slots accept optional cheek risers for NON-AR15 / M16 applications

Compatible with Single-Point® sling mounts

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

 

Included Accessories

Rubber Butt-Pad, 0.30" (Removable)

Specifications

CTR™ Military Carbine Stock (w/ Butt Cap)

Weight, Stock Body: 0.48 lb.

Weight, w/ Receiver Extension: 0.79 lb.

Length, Stock Body: 6.60 in.

LOP Adjustment Range: 3.3 in.

LOP, M4 Collapsed: 10.1 in.

LOP, M4 Extended: 13.4 in.

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

 

** Mounting Standard Rubber Butt-Pad adds 0.30 in. LOP and 0.09 lb. Optional Extended Rubber Butt-Pad, 0.55" adds 0.25 in. LOP and 0.02 lb. vs. standard pad and may be used with either extended-length (slant-back) or standard-length (flat-back) M4 Carbine Receiver Extensions. Butt-pads are compatible with UBR™, ACS, CTR and MOE carbine stocks.

*** Specifications based on standard-length (flat-back) M4 Carbine Receiver Extension and may vary depending on tube specifications. 

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.

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 www.magpul.com. Always test fire your weapon before using it in an operational environment.

 

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.