The Magpul CTR Stock (Compact/Type Restricted) is an American retractable stock for AR-15 and M16 rifles, designed by Magpul Industries in Colorado. A benchmark in the AR-15 aftermarket, the CTR stands out for its anti-wobble locking system that eliminates the mechanical play characteristic of mil-spec telescopic stocks.
History and Development of the Magpul CTR Stock
Magpul Industries was founded in 1999 in Colorado by Richard M. Fitzpatrick, a former sergeant in the U.S. Marine Corps’ Force Recon. The company starts with a simple accessory: a quick recovery latch for rifle magazines. Magpul gradually moved towards the design of high-end polymer parts for AR-15, a segment in which it became the world leader in the 2000s.
The CTR Stock is part of the brand’s range of telescopic stocks, alongside the MOE and the STR. Designed as an improvement on the original M4 mil-spec stocks, the CTR introduces an additional friction locking system that presses the stock against the buffer tube, removing the mechanical play criticized on standard M4 stocks. This innovation has made the CTR the most copied retractable stock on the AR-15 market, equipping both civilian rifles and professional configurations.
Technical Specifications
| Feature | Specification |
|---|---|
| Designation | Magpul CTR Carbine Stock |
| Manufacturer part number | MAG310 (Mil-Spec) |
| Country of Origin | United States (Colorado) |
| Manufacturer | Magpul Industries Corp |
| Type | Carbine Retractable Stock for AR-15/M16 |
| Compatibility | Mil-spec carbine buffer tube (Colt, Armalite, S&W, LMT…) |
| Material: | High-strength reinforced polymer |
| Weight (stock only) | 250 g (8.8 oz) |
| Weight (with buffer tube) | 363 g (12.8 oz) |
| Maximum length | 175 mm (6.9 inches) |
| Adjustment Range (LOP) | 84 mm (3.3 inches) |
| 6-notch | adjustment positions |
| Ambidextrous QD strap attachment + side buckles | |
| Available colours | Black, FDE, Stealth Grey, OD Green, Plum |
Operation and Technical Particularities
The CTR is based on a profiled A-frame profile that reduces snagging with the equipment and protects the release lever from unintentional manipulation. This protects the adjustment lever under a protrusion of the stock, which prevents accidental folding when carrying on a webbing or leaning against a surface.
The central innovation of the CTR is its additional friction lock: a knurled side screw allows the user to clamp the stock against the buffer tube, eliminating the mechanical play inherent in the telescopic system. This feature, absent on the original M4, significantly improves the shooter’s stability and aiming accuracy. The CTR also incorporates an ambidextrous QD at the back that accepts any standard push-button pivot, as well as two side loops for classic straps. The butt plate is made of non-slip rubberized polymer, ideal for shooting in bulletproof vests.
Variants and Versions
The CTR range is available in two distinct technical versions. The Mil-Spec CTR (reference MAG310) is sized for mil-spec buffer tubes, standard on the majority of AR-15s on the market. The CTR Commercial (reference MAG311) fits the wider commercial diameter buffer tubes fitted to some old civilian rifles. In terms of colours, the CTR is available in Black, Flat Dark Earth (FDE), Stealth Grey, OD Green and Plum, allowing for aesthetic pairing with other Magpul accessories. Magpul offers in the same family the STR (Storage/Type Restricted) which adds battery compartments, as well as the MOE and the MOE SL for tighter budgets.
Users and Areas of Use
The Magpul CTR is commonly used in civilian AR-15 configurations, sport rifles (3-Gun, USPSA carbine), semi-automatic shotguns on AR platforms, as well as many military and police configurations. Several American and European special units have adopted the CTR for its stability and durability qualities. Its popularity in sport shooting is due to its value for money: it offers a substantial improvement over the original M4 stocks at a reduced cost. The CTR is also a standard in so-called “clone” configurations replicating the rifles of American Tier 1 military operators.
Civil Possession in Switzerland
In Switzerland, the Magpul CTR Stock is freely available for purchase from specialist gunsmiths and AR-15 accessory retailers. As a weapon part (stock), it is free to acquire and does not require a special licence within the meaning of the Federal Weapons Act (Arms Act). Mounting the CTR on an AR-15 civilian semi-automatic rifle does not change the legal status of the weapon. Owners of mil-surplus AR-15 rifles (e.g. modified SIG 550 or imported American platform) simply need to check the compatibility of the buffer tube, mil-spec being the near-universal standard on modern rifles. As the stock is not an essential part of the weapon, its replacement is accepted without formality by the cantonal authorities.
Conclusion
The Magpul CTR Stock represents one of the most iconic and copied AR-15 accessories on the market. Its combination of polymer strength, neat ergonomics, and anti-wobble system has ensured it a lasting place in tactical rifle configurations. A reference for both civilian and military AR rifles, the CTR continues to embody the Magpul approach: reliable, robust and technically advanced accessories for the AR-15 platform.
