AR-15 Stock

AR-15 Buttstock Overview

An AR-15 buttstock is the rear-mounted shoulder contact component that attaches to the buffer tube (receiver extension) and provides a stable cheek weld, length of pull adjustment, and recoil transfer surface for the shooter. The buttstock is the primary interface between the rifle and the shooter's shoulder, and buttstock selection affects accuracy, comfort, and weapon handling across all shooting positions.

AR-15 buttstocks are available in 3 main configurations: collapsible (telescoping), fixed, and adjustable. TactaBlue stocks AR-15 buttstocks from Magpul, B5 Systems, Bravo Company Manufacturing (BCM), Mission First Tactical (MFT), VLTOR, and other manufacturers.

Types of AR-15 Buttstocks

AR-15 buttstocks fall into 3 categories based on their adjustment mechanism: collapsible, fixed, and precision adjustable.

Collapsible (Telescoping) Buttstocks

Collapsible buttstocks slide along a mil-spec or commercial-spec carbine buffer tube and lock into 4 to 6 positions that adjust length of pull (LOP) from approximately 10.5 to 14.5 inches (267-368 mm). A spring-loaded lever or latch on the bottom of the stock engages notches machined into the buffer tube to lock the stock at each position. Collapsible buttstocks are the most common AR-15 stock type and are standard on M4-pattern carbines.

The Magpul MOE (Magpul Original Equipment) Carbine Stock weighs 7.1 oz (201 g) and fits mil-spec buffer tubes with a 1.148-inch (29.2 mm) outer diameter. The Magpul CTR (Compact/Type Restricted) Stock adds a friction lock lever that eliminates rattle between the stock and buffer tube, weighing 7.5 oz (213 g). The B5 Systems SOPMOD Bravo Stock weighs 8.4 oz (238 g) and features an integrated wide cheek weld designed for use with optics.

Fixed Buttstocks

Fixed buttstocks mount to rifle-length buffer tubes and do not adjust for length of pull. Fixed stocks provide a consistent cheek weld height and a rigid connection to the buffer tube that eliminates movement between the stock and receiver extension. The Magpul MOE Rifle Stock weighs 8.6 oz (244 g) and fits A2/rifle-length buffer tubes with a 1.25-inch (31.8 mm) outer diameter. The A2 buttstock is the original fixed stock used on the M16A2 rifle and features a hinged buttplate with a storage compartment for cleaning kits.

Fixed stocks set length of pull at a single position, typically 13.5 inches (343 mm) for standard A2 stocks. Fixed stocks are required in states that prohibit adjustable or collapsible features on semi-automatic rifles, including California, New York, and New Jersey under current featureless rifle regulations. Check state and local laws before selecting a fixed or collapsible buttstock.

Precision Adjustable Buttstocks

Precision adjustable buttstocks provide independent adjustment of length of pull and cheek riser height for optimized shooter fit behind magnified optics. The Magpul PRS (Precision Rifle/Sniper) Gen3 Stock weighs 23.0 oz (652 g) and offers tool-less LOP adjustment from 14.44 to 15.54 inches (367-395 mm) and cheek riser height adjustment of 0.75 inches (19 mm). The Luth-AR MBA-1 (Modular Buttstock Assembly) weighs 17.0 oz (482 g) and provides LOP and cheek height adjustment with locking thumb wheels.

Precision stocks mount to rifle-length or carbine-length buffer tubes depending on the model. The Magpul PRS Gen3 fits both mil-spec carbine and A2 rifle buffer tubes using included adapters. Precision adjustable stocks are designed for bench rest, prone shooting, and long-range applications where consistent cheek weld and eye relief alignment are priorities.

Buffer Tube Compatibility

AR-15 buttstock compatibility depends on 2 buffer tube specifications: mil-spec vs commercial-spec diameter and carbine vs rifle length.

Mil-Spec vs Commercial-Spec Buffer Tubes

Mil-spec carbine buffer tubes have an outer diameter of 1.148 inches (29.2 mm) and use a flat back surface where the stock contacts the receiver. Commercial-spec buffer tubes have an outer diameter of 1.168 inches (29.7 mm) and use an angled back surface. The 0.020-inch (0.5 mm) diameter difference means a mil-spec stock does not lock securely on a commercial-spec tube, and a commercial-spec stock wobbles on a mil-spec tube. Mil-spec is the standard for military, law enforcement, and most aftermarket AR-15 builds. Verify the buffer tube specification before purchasing a collapsible buttstock.

Carbine vs Rifle Buffer Tubes

Carbine buffer tubes measure 7.25 inches (184 mm) in length and accept collapsible stocks. Rifle-length buffer tubes measure 9.625 inches (244 mm) and accept fixed stocks. The 2 buffer tube types use different buffer weights and spring lengths. A collapsible stock does not mount on a rifle-length tube, and a fixed rifle stock does not mount on a carbine tube without an adapter.

Buttstock Features

AR-15 buttstock selection depends on 5 key features: cheek weld, length of pull range, material, storage, and sling attachment.

Cheek Weld

Cheek weld is the contact point between the shooter's cheek and the stock surface that determines consistent head and eye position behind the sights or optic. Stocks with a wider cheek weld surface of 1.5-2.0 inches (38-51 mm) provide more consistent head positioning than narrow stocks. The B5 Systems SOPMOD Bravo and Enhanced stocks feature integrated wide cheek welds designed for use with Low Power Variable Optics (LPVO) and red dot sights mounted at standard AR-15 height. The Magpul CTR and MOE stocks use a narrower cheek profile suited for iron sights and low-mount optics.

Length of Pull

Length of pull (LOP) is the distance from the trigger face to the back of the buttstock. Correct LOP positions the shooter's trigger finger on the trigger face at a 90-degree bend in the first knuckle. The standard AR-15 LOP range is 10.5-14.5 inches (267-368 mm) for collapsible stocks and 13.5 inches (343 mm) for fixed A2 stocks. Shorter LOP settings accommodate body armor, plate carriers, and shooters with shorter arms. Longer LOP settings suit shooters with longer arms and bench rest shooting positions.

Material and Construction

AR-15 buttstocks are manufactured from 3 primary materials: reinforced polymer, aluminum, and carbon fiber.

• Reinforced polymer: The most common buttstock material, using glass-filled nylon or proprietary polymer blends. Magpul buttstocks use reinforced polymer that withstands temperatures from -40°F to 180°F (-40°C to 82°C). Polymer stocks weigh 7-10 oz (198-283 g) for collapsible models.
• Aluminum: Used in precision stocks and skeletonized lightweight designs. Aluminum stocks weigh 10-23 oz (283-652 g) depending on design complexity. The VLTOR IMOD stock uses an aluminum buttpad frame with polymer body.
• Carbon fiber: Used in ultralight competition stocks. Carbon fiber stocks weigh 4-6 oz (113-170 g) and cost $150-$300. Carbon fiber provides the highest strength-to-weight ratio.

Storage Compartments

Several AR-15 buttstocks include built-in storage compartments for batteries, cleaning kits, or spare parts. The A2 fixed stock features a hinged buttplate that opens to a storage cavity measuring approximately 5.5 inches (140 mm) in depth. The Magpul MOE and CTR stocks accept optional storage kits (Magpul Enhanced Rubber Butt-Pad with storage compartment). The B5 Systems Enhanced SOPMOD stock includes 2 waterproof battery storage tubes in the cheek weld area for CR123A or AA batteries.

Sling Attachment Points

AR-15 buttstocks include sling attachment points in 3 configurations: integrated Quick Detach (QD) sockets, sling loops, and ambidextrous attachment plates. The Magpul CTR and MOE stocks include a rear sling loop and accept QD sling swivels through the rear receiver end plate. The B5 Systems SOPMOD stocks include integrated ambidextrous QD sling sockets molded into the stock body. Rear sling attachment connects the buttstock to a rifle sling for carry and shooting support.

Top AR-15 Buttstock Brands

Five manufacturers produce the most widely used AR-15 buttstocks: Magpul, B5 Systems, BCM, Mission First Tactical (MFT), and VLTOR.

Magpul Buttstocks

Magpul produces 6 buttstock models for AR-15 platforms: the MOE Carbine, MOE SL (Slim Line), CTR, STR (Storage/Type Restricted), ACS-L (Adaptable Carbine/Storage Lightweight), and PRS Gen3. Magpul buttstocks use reinforced polymer construction, mil-spec buffer tube compatibility (with commercial-spec versions available), and a friction lock mechanism on CTR, STR, and ACS-L models. Magpul buttstock prices range from $30 for the MOE to $230 for the PRS Gen3.

B5 Systems Buttstocks

B5 Systems produces the SOPMOD Bravo and Enhanced SOPMOD stocks. The SOPMOD Bravo weighs 8.4 oz (238 g) and features a wide cheek weld without storage compartments. The Enhanced SOPMOD weighs 10.9 oz (309 g) and adds 2 waterproof battery storage tubes and a wider cheek weld profile. B5 Systems stocks are used by United States Special Operations Command (USSOCOM) units and are designed for mil-spec buffer tubes.

BCM Gunfighter Stock

The Bravo Company Manufacturing (BCM) Gunfighter Stock Mod 0 weighs 6.8 oz (193 g) and uses a snag-free design with a low-profile latch. The BCM Gunfighter is one of the lightest collapsible stocks available and fits mil-spec buffer tubes. The Gunfighter stock features an angled rubber buttpad and a slim profile that reduces snagging during weapon transitions.

Buttstock Installation

To install a collapsible AR-15 buttstock, press the stock's adjustment lever and slide the stock onto the buffer tube from the rear. Push the stock forward until the locking latch clicks into the first notch on the buffer tube. Test each locking position by pulling rearward on the stock to confirm the latch engages securely. No tools are required for collapsible stock installation on a properly assembled buffer tube.

Fixed stock installation requires threading the rifle-length buffer tube into the lower receiver, inserting the buffer and buffer spring, and sliding the fixed stock over the buffer tube. Secure the stock with a stock screw or buttplate screw that threads into the rear of the buffer tube.

Shop AR-15 Buttstocks at TactaBlue

TactaBlue (tactablue.com) stocks AR-15 buttstocks from Magpul, B5 Systems, BCM, Mission First Tactical, VLTOR, and other manufacturers. Browse AR-15 accessories including grips, buffer springs, and slings to complete your AR-15 furniture setup. All buttstocks sold at TactaBlue are authentic, factory-sealed products from authorized distributors.

TactaBlue ships within one business day and offers free ground shipping on all contiguous U.S. orders. A 30-day return policy applies to eligible items. For questions, contact support@tactablue.com, Monday through Friday, 10 AM to 6 PM ET.