LUTH AR MBA4F SKULLATON STOCK ASSEMBLY FDE

The Luth-AR MBA-4F Skullaton Stock Assembly in Flat Dark Earth is a lightweight, purpose-built replacement buttstock for AR carbine rifles. Weighing just 9.5 ounces, this skullaton-design stock pairs durability with minimal added weight—ideal if you're running a .223 or .308 AR carbine and want a modern alternative to heavier fixed or standard adjustable stocks. The glass-filled nylon construction delivers the strength you need for field use without compromise, and the minimalist profile gives your carbine a distinctly contemporary look while keeping ergonomics front and center.

Installation is straightforward: the MBA-4F mounts to standard mil-spec or commercial buffer tubes and uses 4 of the 6 available positions, so you won't need any special adapters for most common setups. The included Picatinny rail opens the door to accessories, and Luth-AR's anti-rattle set screw design keeps things solid in the field without the noise. If you need a higher cheek rest or longer pull for your shooting style, the stock accepts Luth-AR's optional cheek piece and extended butt plate assemblies—meaning you can fine-tune fit without buying an entirely new stock.

One thing to know upfront: this carbine stock is engineered for .223 and .308 applications. It's not rated for large-bore calibers like .338 Lapua or .50 BMG, and it won't work with A2 buffer tubes—if you're running that setup, Luth-AR's MBA-1 or MBA-2 rifle stocks are the right choice. Some aftermarket commercial tubes over 1.1172 inches in diameter may not fit either, so measure before you order if you've upgraded your buffer tube.

Key Features

• Lightweight skullaton design at 9.5 ounces—minimal weight penalty for a quality stock
• Glass-filled nylon construction for field-proven durability
• Fits standard mil-spec and commercial buffer tubes (uses 4 of 6 positions)
• Integrated Picatinny rail for optics and accessories
• Anti-rattle set screw for solid, quiet mounting
• Compatible with optional cheek pieces and extended butt plates for customized fit
• Quick and easy to install—no gunsmithing required

Specifications

Frequently Asked Questions

Will the MBA-4F fit my AR carbine?

The MBA-4F is designed for .223 and .308 AR carbines with mil-spec or commercial buffer tubes. It will not fit A2 buffer tubes—you'd need an MBA-1 or MBA-2 rifle stock for that setup. If your buffer tube diameter exceeds 1.1172 inches, check compatibility before purchasing. The stock is not suitable for large-bore calibers like .338 Lapua or .50 BMG.

Can I adjust the length of pull with this stock?

The MBA-4F itself occupies 4 of the 6 positions on a mil-spec or commercial tube, so you have some adjustability by sliding it along the tube. For additional length of pull, you can add Luth-AR's optional butt plate assembly or 3-axis butt plate assembly, which add approximately 1 1/16 inches. Similarly, the optional cheek piece adds roughly 1 inch of cheek height.

How much does it weigh compared to other stocks?

The MBA-4F weighs just 9.5 ounces, making it a lightweight option for carbine builds where you want to minimize unnecessary weight without sacrificing strength.

What's included and how hard is it to install?

The MBA-4F stock assembly comes ready to mount directly to your existing mil-spec or commercial buffer tube. Installation is quick and straightforward—no special tools or gunsmithing required. Simply slide it onto your tube and secure it with the included anti-rattle set screw.