What’s the difference between a mil-spec and commercial buffer tube?

Mil-spec tubes are 1.14” with a flat back. Commercial tubes are 1.17” and have a slanted end. They are not cross-compatible.

Do buffer tube kits include springs and castle nuts?

Yes. Our buffer tube kits include a recoil spring, buffer, castle nut, and end plate—everything needed to attach a stock.

Can I use a rifle-length buffer tube on a carbine?

No. Rifle-length tubes are for fixed stocks and require a rifle buffer and spring. Carbine setups use shorter tubes and different components.

AR-15 Buffer Tube | Mil-Spec, Commercial & Pistol Kits

Name: AR-15 Buffer Tube
Brand: Mounts Plus
Availability: InStock

AR15 Castle Nut

AR-15 Buffer Tube Kit

Commercial Buffer Tube

Milspec Buffer Tube

Buffer Tube Wrench

AR 15 Buffer Tube Back Plate

Commercial vs. Mil-Spec Buffer Tube

Carbon Fiber Buffer Tube

What buffer tube do I need for my AR-15?

What is the purpose of the buffer tube on an AR-15?

AR Pistol Buffer Tube

A2 Rifle Buffer Tube

**ATI AR-15 Commercial Buffer Tube** $43.28

**ATI AR-15 Buffer Tube Commercial Package** $66.65

**ATI AR-15 Mil-Spec Buffer Tube Package** $63.12

**ATI AR-15 Buffer Tube - Mil-Spec Buffer Tube** $43.28

**ATI AR-15 Pistol Buffer Tube Assembly** $63.12

**Deltac AR-15 Mil Spec Buffer Tube Kit with Dual Loop Sling End Plate** $79.92

**DELTAC AR-15 Buffer Tube Mil-Spec - MADE IN USA** $27.49

**Timber Creek Buffer Tube - Mil-Spec AR15 Buffer Tube** $31.99

**Timber Creek Carbon Fiber Buffer Tube - Mil-Spec AR-15 Buffer Tube Kit** $71.99

**VISM AR-15 Buffer Tube / Aluminum Commercial Buffer Tube with Castle Nut** $17.99

**VISM AR-15 Buffer Tube / Aluminum Mil Spec Buffer Tube with Castle Nut** $18.99

**UTG PRO AR15 6-Position Receiver Extension Tube, Mil-Spec, Matte Black** $21.97

**UTG PRO AR15 6-Position Receiver Extension Tube – Mil-Spec, FDE Cerakote®** $37.97

**UTG PRO AR Pistol Receiver Extension Tube** $32.97

**BCM Mil-Spec Carbine Buffer Tube** $38.95

**Luth-AR 223/308 A2 Rifle Buffer Tube** $30.07

**Luth-AR Carbine Buffer Tube – Mil-Spec – 6 Position** $24.90

**Aero Precision AR15/AR10 Enhanced Carbine Buffer Tube - Kodiak Brown Anodized** $48.99

**Aero Precision AR15/AR10 Enhanced Carbine Buffer Tube - OD Green Anodized** $48.99

**BCM Milspec Carbine Stock Hardware MOUNTING KIT (Mil-Spec)** $57.95

**Aero AR15 Enhanced Carbine Buffer Kit** $76.99

**AR15 Enhanced Carbine Buffer Kit – Kodiak Brown Anodized** $76.99

**CMC Triggers AR-15 Mil-Spec Carbine Buffer Tube Kit – Enhanced QD** $60.27

**Luth-AR Mil-Spec Carbine Buffer Assembly – .223/5.56** $48.83

AR-15 Buffer Tubes for Every Build: Mil-Spec, Commercial & Pistol

When you’re building or upgrading an AR-15, choosing the right buffer tube is a must. The buffer tube isn’t just a place to attach your stock—it’s key to smooth cycling, proper recoil management, and long-term durability.

At Mounts Plus, we stock AR-15 buffer tubes and complete kits designed for rifles and pistols, whether you're looking for mil-spec, commercial, rifle-length, or pistol buffer tubes.

What’s the Difference Between AR-15 Buffer Tube Types?

Mil-Spec Buffer Tubes

Standard for most AR-15 rifles today
Smaller diameter, tighter tolerances
Fits mil-spec collapsible stocks

Commercial Buffer Tubes

Slightly larger diameter than mil-spec
Fits older or commercial-spec stocks

Rifle-Length Buffer Tubes

Fixed length for A2-style or DMR rifle stocks
No collapsible feature—great for precision setups

Pistol Buffer Tubes

Designed specifically for AR pistols
Supports stabilizing braces and minimalist builds

If you’re not sure which you need, mil-spec is the safest default for modern builds.

Complete Buffer Tube Kits Available

For easier builds or replacements, we also carry complete AR-15 buffer tube kits. These include:

Buffer tube
Recoil buffer
Recoil spring
End plate
Castle nut

All components are matched for compatibility, saving you from hunting down individual parts.

Why Shop AR-15 Buffer Tubes with Mounts Plus?

Top brands: Aero Precision, ATI Outdoors, BCM, Timber Creek
Fast U.S. shipping
Expert customer support
Full kits and standalone tubes available
Options for rifle, pistol, and custom AR-15 builds

Looking to complete your AR-15 build? Check out these essential components:

Pair your buffer tube with a full AR-15 Buffer Tube Kit for complete installation parts.
Upgrade your setup with AR-15 Buttstocks compatible with mil-spec and commercial tubes.
For pistol builds, browse our AR-15 Pistol Buffer Tubes made for stabilizing braces.
Don't forget to grab an AR-15 Lower Parts Kit to complete your lower assembly.
See our AR-15 Accessories for grips, sights, and other upgrade parts.

Frequently Asked Questions (FAQ)

Q: How can I tell if I need a mil-spec or commercial buffer tube?
A: Mil-spec tubes fit most modern AR-15 builds. If unsure, check your stock’s markings or diameter.

Q: Will a pistol buffer tube work with a collapsible stock?
A: No. Pistol buffer tubes are for braces only and don’t accept stocks.

Q: Do rifle-length buffer tubes fit collapsible stocks?
A: No. Rifle-length tubes are designed for fixed stocks like the A2 style.

Q: What’s included in your buffer tube kits?
A: Our kits include the buffer tube, recoil buffer, spring, end plate, and castle nut—everything you need to get started.

Every buffer tube and kit we carry is tested and selected for quality and fitment. Whether you’re building a rifle for competition, duty, or home defense, we have the right AR-15 buffer tube to match your needs.