$51.65
Availability: In Stock
A Double Star mil-spec buffer tube assembly is the backbone of any AR-15 or AR-style carbine build that needs a properly fitted, adjustable stock. Whether you're assembling a custom rifle from scratch, swapping out a fixed stock for an M4-style adjustable one, or upgrading a civilian carbine, this machined aluminum receiver extension gives you the adjustability and durability that shooters expect from a mil-spec platform.
Double Star machined this tube from lightweight aluminum extrusion and hardcoat anodized it for corrosion resistance and a clean finish that stands up to field use. Inside, a dry film lubricant coating keeps the buffer and spring moving smoothly—no gumming up, no excess grease to collect dust. The underside features six precision-machined notches, giving you multiple length-of-pull settings so you can dial in the fit for your shooting position, gear setup, or body geometry. That flexibility is especially useful if your rifle gets passed between shooters or you're dialing in the perfect ergonomics for your style.
Keep in mind: this is the tube itself. You'll need to source a carbine recoil spring, buffer, lock ring, and receiver plate separately—all standard parts available from any AR builder's supplier. If you already have those pieces on hand or know what you need, this tube gives you a solid, tested foundation for a functional, reliable carbine.
| Brand | Double Star |
| Type | Mil-Spec Buffer Tube Assembly (Receiver Extension) |
| Material | Machined Aluminum |
| Finish | Hardcoat Anodized with Dry Film Lube (Interior) |
| Stock Compatibility | M4-Style Adjustable Carbine Buttstock |
| Length-of-Pull Options | Six Notched Positions |
This tube is one component of the recoil system. You'll need to separately acquire a carbine recoil spring, buffer, lock ring, and receiver plate to have a complete, functional assembly.
Yes, this is a mil-spec receiver extension designed to accept M4-style adjustable carbine stocks on AR-15 and AR-pattern carbines.
Yes. Six precision-machined notches on the underside let you select from multiple length-of-pull settings to fit your shooting position and body geometry.
The interior is coated with dry film lubricant, which keeps the buffer and spring moving smoothly without the mess or maintenance issues of wet grease or oil.
SKU: 197548018 • Weight: 0.3oz