The Complete A2 Stock and Rifle-Length Recoil System

The Luth-AR BS-A2K A2 Butt Stock Kit gives an AR-15 builder the complete rear stock and rifle-length recoil-system package needed for a traditional fixed A2 configuration.

This is more than an A2 stock shell. Luth-AR packages the fixed A2 buttstock, rifle receiver extension, .223/5.56 rifle buffer, rifle buffer spring, aluminum A2 spacer and upper stock screw together so the major components of the fixed-stock system are already matched and ready for installation.

For a traditional 20-inch rifle, retro-inspired build, service-rifle-style AR or simply a shooter who prefers a solid fixed stock over an adjustable carbine stock, the BS-A2K provides the classic A2 configuration in one package.

Why Choose an A2 Fixed Stock?

The A2 stock represents a very different approach from the collapsible M4-style stock.

Instead of adjusting length of pull by sliding along a carbine receiver extension, the A2 uses a solid fixed stock and rifle-length receiver extension. The result is a stable shoulder interface with no sliding stock body, adjustment latch or exposed carbine tube.

A fixed stock also provides a long, consistent cheek surface and works naturally with traditional rifle-length AR configurations.

Complete Rifle-Length Buffer System Included

The BS-A2K includes the major components required to establish a conventional AR-15 rifle-length recoil system:

• A2 Butt Stock – BS-A2
• A2 Upper Butt Stock Screw – A2-01
• Aluminum A2 Spacer – A2S-01
• Rifle Receiver Extension – BS-09
• .223 / 5.56 Rifle Buffer Spring – BS-10B
• .223 / 5.56 Rifle Buffer – BS-11

That makes the kit especially convenient when converting a lower from a carbine-style stock system or building a fixed-stock lower from the beginning.

Rifle-Length Buffer System — Not a Carbine Kit

The included receiver extension, buffer and spring are rifle-length components.

They should not be confused with the shorter receiver extension, buffer and spring used in a conventional collapsible M4-style carbine system.

The dimensions of the recoil components are designed to work together. Do not substitute a carbine buffer into the included rifle receiver extension or mix rifle and carbine recoil components without understanding the dimensional differences between the two systems.

The A2 Spacer Matters

The A2 stock is longer than the earlier A1 pattern, and the included aluminum spacer occupies the additional space between the rear of the rifle receiver extension and the A2 buttstock.

The supplied longer A2 stock screw then secures the complete assembly.

Including the correct spacer and screw is a small detail that makes the complete BS-A2K kit more useful than purchasing an A2 stock body by itself.

Foam-Filled Stock Body

Luth-AR describes its A2 stock as foam filled. The internal foam helps give the otherwise hollow polymer stock body a more substantial feel while retaining the familiar external A2 profile.

The stock uses a polymer trap door at the butt, retaining the classic A2 storage-compartment design.

Classic A2 Storage Compartment

The hinged trap door provides access to the internal buttstock storage compartment traditionally used for compact cleaning gear or other small field items.

It is one of the features that distinguishes a traditional A2 rifle stock from minimalist fixed stocks and collapsible carbine furniture.

A2 Length and Rifle Ergonomics

The A2 is a full-size fixed rifle stock. That makes it particularly comfortable for shooters who prefer a longer, consistent length of pull and a broad cheek surface rather than the compact dimensions of a collapsed carbine stock.

On a traditionally configured AR-15 rifle, the A2 stock also places some additional mass toward the rear of the firearm, which can help balance longer barrels and full-length handguards.

A Natural Choice for Traditional AR Builds

The A2 configuration makes particular sense for:

• 20-inch AR-15 rifle builds
• A2-style and service-rifle-inspired rifles
• Retro-influenced builds where an A1-length stock is not required
• Precision or bench-oriented rifles where an adjustable carbine stock is unnecessary
• General-purpose rifles where simplicity and a consistent stock position are preferred

Black A2 Configuration

This listing is for BS-A2K in Black. Luth-AR also manufactures a separate OD Green version under SKU BS-A2K-G.

Using the exact SKU distinction prevents confusion when matching the stock to the rest of the rifle's furniture.

Made in America

Luth-AR identifies the A2 Butt Stock Kit as an American-made product.

For a builder who wants the familiar fixed-stock geometry of the traditional AR rifle and would rather purchase the complete recoil system together than assemble it component by component, the BS-A2K is a straightforward solution.

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