Aero Precision M5 Receiver Extension Buffer Tube Assembly 6-Position Mil-Spec Diameter LR-308 Carbine Aluminum Black

Building a .308 AR platform rifle starts with the right foundation, and the Aero Precision M5 LR-308 6-position mil-spec carbine buffer tube assembly gives you exactly that. This US-made complete buffer tube kit is designed for AR .308 pattern rifles and handles the mechanical basics so you can focus on configuring the rest of your build. The 6-position tube lets you dial in length of pull with your stock of choice, whether you're setting up for prone shooting, tactical work, or hunting from a rest.

The buffer tube itself is machined from 7075-T6 aluminum—the same high-strength alloy used in aerospace applications—so it'll stand up to extended use and still keep weight down at 10.2 ounces. Aero Precision includes everything you need to complete the rear end assembly: the buffer tube, a .308-pattern buffer, the recoil spring, an end plate, and a castle nut. You're just choosing and adding an aftermarket stock to finish the job, which means you get to pick a cheek riser, storage, or ergonomics that match your shooting style.

This is the kind of no-nonsense component that appeals to precision rifle builders and hunters who value consistency and durability. If you're assembling a long-range .308 or upgrading an existing rifle platform, a quality buffer tube assembly is a smart, foundational choice that won't need replacing.

Key Features

• Six adjustable positions for flexible stock length of pull
• 7075-T6 aluminum construction for durability and lightweight performance
• Mil-spec design compatible with AR .308 pattern rifles
• Complete kit includes buffer, spring, end plate, and castle nut
• Built in the USA
• Total weight: 10.2 ounces

Specifications

Frequently Asked Questions

What rifle platform is this buffer tube assembly designed for?

The Aero Precision M5 buffer tube is built for AR .308 / LR-308 pattern rifles. It is not compatible with AR-15 (.223 Remington) platforms, which use a different buffer tube standard.

What comes in the kit and what do I still need to add?

The kit includes the buffer tube, a .308 buffer, recoil spring, end plate, and castle nut. You'll need to source and install an aftermarket stock of your choice to complete the assembly.

Why does a 6-position buffer tube matter?

Six adjustable positions let you set the length of pull to fit your body, shooting position, and gear. Whether you're wearing a plate carrier, shooting prone, or shooting in shirt sleeves, you can dial in the exact fit without adding bulk or weight.

Is this mil-spec and will it work with standard .308 accessories?

Yes—it's designed to mil-spec standards for the AR .308 platform, so it will accept standard aftermarket stocks and other mil-spec-pattern components built for the M5 LR-308 system.