Frequently asked questions.

We ship within the United States only, typically processing orders within 1–2 business days; free shipping on orders over $500. See the full shipping policy for carrier options, Route package protection, and the California shipping requirements.

Log in to your account to view your order history and tracking information. You will also receive a shipping-confirmation email with tracking information once your order leaves our facility.

Orders are typically processed within 1–2 business days. If you have not received tracking information within five business days, please contact us. We will notify you if your order is delayed for any reason.

Please review our Shipping Policy for additional information.

30-day return window on unused products in original packaging — see the returns policy for condition requirements and the RMA process.

Limited lifetime warranty on A3-manufactured products. See the warranty page for more information.

We do not offer international shipping at this time. If you are an international customer, we encourage you to shop with one of our trusted dealers.

Yes — free shipping on orders over $500.

Every product page lists explicit platform compatibility — check the "Fits these firearms" callout, or browse from your platform's page so everything shown is fit-checked for it.

Our Shop by Firearm selection highlights some of the most popular platforms on the market. If your firearm is not listed, we probably still offer compatible parts that use universal mounting interfaces and do not require a platform-specific adapter or mount.

If you're unsure, contact us at tech@a3industries.com. Our technical support team can help you navigate the catalog and identify compatible products.

Yes. Our modular braces can be converted into stocks by replacing the brace component with the appropriate stock component. We purposely sell these components individually so you can reconfigure your setup without replacing the entire assembly.

This allows you to convert your brace after registering your firearm as an SBR or to use the assembly as a stock on an existing rifle or registered SBR.

Always ensure that your firearm's configuration complies with all applicable federal, state, and local laws before installing a stock. A3 Industries cannot provide legal advice.

Direct-fit stocks and braces are designed for specific firearm platforms and attach directly to the firearm's factory mounting point or built-in hinge mechanism.

1913-mounted products attach to a standardized rear Picatinny rail found on many modern firearms. If your firearm does not have a rear 1913 rail, we may offer a platform-specific adapter that adds one, allowing you to install one of our 1913 stocks or braces.

The right length depends on your firearm, shooting position, body size, and preference. Shorter configurations keep the firearm compact and work well with body armor or a more squared shooting stance, while longer configurations provide a more traditional length of pull.

We highly recommend comparing the listed dimensions with a stock or brace that already feels comfortable to you. Adjustable models offer the most flexibility if you are unsure. For a personalized recommendation, contact tech@a3industries.com with your firearm model and preferred setup.

Product-specific installation instructions can be found on the applicable product page and on our Installation Instructions page. Some universal products do not include separate instructions because they install like standard M-LOK or Picatinny accessories.

If you cannot find the instructions you need or are having difficulty with installation, contact our technical support team at tech@a3industries.com.

Most of our products can be installed using standard hex (Allen) or Torx wrenches. If a product requires a proprietary or specialty tool, the necessary tool will be included with the product.

We cannot accept your firearm for installation work. However, depending on the product, we may be able to assemble compatible A3 components together before shipping your order.

Assembly availability is determined on a case-by-case basis. If you have installation concerns or would like to request assembly, please contact orders@a3industries.com before placing your order.

Yes. We include the necessary mounting hardware with every product we manufacture. Some products are designed to reuse your firearm's factory hardware; when applicable, this will be noted on the product page or in the installation instructions.

No. The TRIAD is a chassis that houses a user-supplied mil-spec AR lower receiver. The lower receiver remains the serialized component.

No. The TRIAD is an unserialized chassis, not a firearm or receiver, so it can be shipped directly to your doorstep.

You will need a mil-spec AR lower receiver, a bolt catch with its spring, pin, and plunger, a compatible flat-faced trigger, and a compatible bufferless upper receiver assembly. A complete AR lower parts kit is not required, as the TRIAD includes the remaining internal and assembly components.

See below for compatible lower receivers and upper assemblies.

You will need a standard, no frills, Mil-spec lower receiver. These are by far the most common and least expensive receiver available. No receivers with integrated trigger guards. Integrated trigger guards swell downward, which would have required a taller chassis to accommodate. No billet receivers. There are simply too many companies making their own billet lower receivers. Most manufacturers have their own unique external features to distinguish them from the rest, and these are all in critical areas that keep the chassis slim. Compatibility would have required a much bulkier chassis to accommodate. Most of these features are cosmetic anyway and since they won't be seen inside the chassis, there is simply no reason to run a billet lower receiver in the TRIAD.

The TRIAD requires a bufferless upper receiver. Traditional AR uppers rely on a rear buffer tube, buffer spring, and buffer and are not compatible.

Compatible uppers include the Foxtrot Mike FM-15, Palmetto State Armory JAKL, Brownells BRN-180, and Matador Arms MAT-9 9mm upper. Some of these uppers are available in multiple calibers, so please review the caliber compatibility information below before purchasing.

The TRIAD is compatible with most single-stage, flat-faced triggers. The trigger face must be flat — a curved trigger will not interface correctly with the TRIAD's linkage. For the best operation, we recommend a short-reset cassette-style trigger rather than a standard mil-spec trigger.

Note: CMC triggers and Radian Vertex triggers are not compatible due to their physical dimensions.

TRIAD assembly is straightforward and can typically be completed in about 30 minutes. The chassis arrives preassembled with the trigger linkage self-contained, adjusted, and tested. All necessary wrenches are included; the only additional tool required is a 3/8-inch-drive ratchet.

Installation involves removing the left chassis half, inserting your AR lower receiver with the trigger and bolt catch already installed, reassembling the chassis, and adjusting the trigger actuator. You will then install the end cap or buttplate for your configuration and mount the M-LOK front takedown lug to the upper receiver.

For a complete walkthrough, view our TRIAD installation instructions.

In its standard configuration, the TRIAD has a 14.25-inch length of pull. Adding our 1.5-inch buttpad spacer increases the LOP to 15.75 inches.

See the overall-length question below for information on how overall-length requirements may affect your configuration.

A standard rifle configuration using the TRIAD chassis and a 16-inch Foxtrot Mike upper weighs approximately 6 pounds, 8 ounces without an optic or accessories.

For comparison, the Steyr AUG and IWI Tavor X95 each weigh approximately 7 pounds, 9 ounces, while the Springfield Armory Hellion weighs approximately 8 pounds.

The TRIAD measures 24.75 inches from the end of the barrel — not including the muzzle device — to the rear of the buttpad.

Overall length note: the TRIAD system is very compact. Our TRIAD chassis ships with two butt-plates: a standard compact butt-plate and a 1.5-inch extended butt-plate, designed to bring the firearm up to 26.25 inches overall. The following configurations achieve a 26-inch (or longer) overall length:

• A 16-inch barreled upper with our 1.5-inch extended butt-plate (provided with the kit)
• An 18-inch barreled upper with our standard butt-plate
• A 16-inch barreled upper with a pinned and welded 1.5-inch (or longer) muzzle brake
• A barreled upper shorter than 16 inches with a pinned and welded suppressor

See the TRIAD Disclaimer for the applicable federal definitions. It is your responsibility to ensure compliance with all federal, state, and local laws and regulations.

Yes, but compatibility depends on the upper family. Uppers from the same manufacturer can generally be swapped without modifying the TRIAD. For example, you can switch between 16-inch and 12.5-inch Foxtrot Mike uppers with no changes.

Foxtrot Mike and JAKL uppers use different internal buffer components, so switching between them requires swapping those components or using a separately configured TRIAD assembly.

A BRN-180 upper can be used with a JAKL-configured TRIAD and should function properly. However, because the BRN-180 handguard is narrower than the JAKL handguard, there will be a visible gap between the handguard and chassis.

Yes. Once your Form 1 has been approved, you can install our buttplate upgrade kit. The kit includes the lower buttplate support, buttplate, 1.5-inch extension, buttpad, and all required mounting hardware.

The kit is available in the TRIAD collection.

We have successfully tested the TRIAD in 5.56×45mm, .300 BLK, .350 Legend, 6mm ARC, 6.5 Grendel, 7.62×39mm, and 9mm.

For 7.62×39mm configurations, the TRIAD is compatible with the BRN-180 upper because it uses AR-pattern ASC or Duramag magazines. The 7.62×39mm PSA JAKL requires AK-pattern rock-and-lock magazines, which are not compatible with the TRIAD chassis.

The HDA3 is a modular stock/brace system developed from a collaboration between Haga Defense and A3 Industries. The HDA3 was designed specifically to integrate seamlessly across dozens of firearm platforms without sacrificing strength or aesthetics to do so.

Virtually any platform that supports a 1913 Picatinny interface or has an available A3 direct-fit adapter.

The HDA3 was quietly released on March 24, 2025. The highly anticipated release was not announced in order to be fair to those that have been on the in-stock email notification lists the longest. The best way to find out when an HDA3 for your firearm will be available is to sign up to be notified by email when in stock. You can do this on the product page.

The core HDA3 stock and brace components will be exactly the same no matter where you get them from but the firearm specific adapters may be different. For example a Bren 2 stock adapter from Haga Defense may have QD sling attachment machined into the aluminum where the A3 Industries variant will have a steel QD socket set into the aluminum adapter. Or the MP5 adapter from A3 Industries will be nylon while the adapter from Haga Defense will be aluminum. Be sure to check out both Haga Defense and A3 Industries to see all available options. Some options may be available on both websites and some only on one or the other. You can use the part number to identify which adapter a stock or brace has.

Example:
HDA3-MP5-HD-S-LF-BLK - Haga Defense
HDA3-MP5-A3-S-LF-BLK - A3 Industries

To fold the stock, grasp the stock placing your thumb over the top of the folding hinge. Press down with your thumb while lifting up on the stock to dislocate it. This will allow the hinge to fold. Hinges may be pretty stiff to operate when new. They will break in and become easier to operate over time with use.

The HDA3 will initially only be available with a left folding option. Right folding options are planned to be available at a later date as well as kits to convert left folding stocks to right and vice versa.

The initial release will be black only. FDE, ODG and Gray will follow shortly after. No other colors are currently planned.

We offer tiered pricing based on your initial order. Small businesses that want to test our products can qualify for Friends of the Industry pricing with no minimum buy-in. Deeper dealer discounts require an initial buy-in, and full pricing requirements will be provided after your application is reviewed.

No, there is no minimum SKU requirement. However, we offer volume-based discounts, which will be outlined in the pricing sheet provided after your dealer application is approved.

We do not offer a formal drop-shipping program. However, you may enter a different shipping address when placing an order through our website.

No. Approval as an A3 Industries dealer does not provide exclusive sales rights within a specific territory. We may approve additional dealers in the same geographic area.

Dealer orders follow the same fulfillment process as retail orders. Items shown as in stock on our website are available and ready to ship. Our standard processing time is 1–2 business days.

We prefer to coordinate warranty claims through the dealer because it allows us to locate the original order in our system. However, customers may contact us directly if they can provide proof of purchase from an approved A3 dealer.

A3 Industries does not provide legal advice on firearms regulations. Compliance with federal, state, and local laws regarding firearm parts, accessories, and registration is the responsibility of the buyer.

Some products may be restricted or prohibited in certain states, territories, counties, or municipalities, and A3 Industries will not ship a product where its sale or delivery is prohibited — see State and Local Restrictions in the shipping policy. California orders are subject to age and identity verification, adult-signature delivery, and a $10 fee — see the California shipping policy.