Magpul® CTR® Carbine Stock – Commercial-Spec

(10 reviews)
Current Stock:

Magpul Stock CTR M4 Carbine, Commercial

CTR M4 Carbine Collapsible Buttstock / Commercial Model

The patent-pending 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.

Note: There are two basic types of M4 Carbine Receiver Extensions (buffer tubes): Mil-Spec and Commercial. If you have a Mil-Spec extension on your rifle, make sure to order the Military CTR (MAG310). For help identifying which extension is on your rifle, please contact your rifle manufacturer.

Made in the USA


    • Mounts on Commercial Carbine Receiver Extension tube (Not included)
    • Premium chrome-silicon 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**: Extended Rubber Butt-Pad, 0.55" (Removable)

Optional Accessories**

  • Rubber Butt-Pad, 0.30"
  • Cheek Risers (0.25", 0.50", 0.75", 1.5" for NON-M16 applications)


  • CTR Commercial Carbine Stock (w/ Rubber Butt-Pad, 0.55")
  • Weight, Stock Body: 0.57 lb.
  • Weight, w/ Receiver Extension: 0.98 lb.
  • Length, Stock Body: 7.15 in.
  • LOP Adjustment Range: 3.8 in.
  • LOP, M4 Collapsed: 10.4 in.
  • LOP, M4 Extended: 14.5 in.

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

** Removing Extended Rubber Butt-Pad subtracts 0.55 in. LOP and 0.12 lb. Optional Standard Rubber Butt-Pad, 0.30" subtracts 0.25 in. LOP and 0.02 lb. vs. extended pad but may only be used with standard-length (flat-back) M4 Carbine Receiver Extensions only. Butt-pads are compatible with UBR, ACS, CTR, and MOE, carbine stocks.

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


  • 5
    Excellent product

    Posted by Unknown on 17th Nov 2009

    Once again the crew at Magpul have put forth a superior piece of equipment at a reasonable price. This stock replaced a factory issue in seconds. It locks rock solid to the extension tube. The only play in my rig now is that little bit of wiggle between the upper and lower. If cheek weld is an issue they have a solution for that but you do have to purchase it separately. Highly recommend this to the shooter that wants to tighten things up in the rear. QD swivels pop right in for two point mounts. Comes in commercial and mil-spec diameters. One note: I tried to put one on a Rock River Tactical Entry carbine (which is commercial dia) and it did not lock down tight on the tube. I'm sure its something with the tube RRA uses. BTW, the mil-spec didn't fit; I tried that. I've put in calls and emails to their tech support to resolve this issue but (big surprise) noone has gotten back to me. I've had no such problem with the tubes other manufacturers are using.