
Availability: In Stock
The WMD buffer tube carbine NIB-X silver is a mil-spec receiver extension built for AR-platform rifles that need a durable, corrosion-resistant foundation for a collapsible buttstock. WMD Guns machines these tubes from 7075 aluminum extrusion and applies a NiB-X nickel boron coating—a hard, slick finish that stands up to salt, sweat, and harsh field conditions far better than bare aluminum or standard hard-anodize. If you're building or upgrading a carbine and want a buffer tube that won't wear, pit, or require constant maintenance, this is the kind of component that pays for itself in years of worry-free use.
The tube accepts M4-style adjustable carbine buttstocks and offers six adjustment positions, giving you the flexibility to dial in length of pull for different shooting scenarios, clothing layers, or simply dialing it to what feels right behind your gun. The mil-spec diameter and threading are standard across the AR platform, so compatibility isn't a mystery—if your stock is M4-compatible, it'll fit. The silver finish isn't just aesthetics; that NiB-X coating is genuinely harder and more slippery than conventional mil-spec finishes, which means smoother action, easier cleaning, and real corrosion resistance if you're shooting in humid, dusty, or coastal environments.
Whether you're assembling a duty rifle, a precision build, or simply replacing a worn tube on a well-used carbine, WMD's approach here—high-strength alloy, purpose-engineered coating, and tight mil-spec tolerances—means this isn't a throwaway part. It's the kind of detail that separates a rifle you'll trust from one you'll second-guess.
| Material | 7075 Aluminum |
| Finish | NiB-X Nickel Boron (Silver) |
| Tube Type | Mil-Spec Carbine Buffer Tube |
| Buttstock Compatibility | M4-Style Adjustable Carbine (6 positions) |
| Brand | WMD Guns |
Yes. This is a mil-spec carbine receiver extension, and it accepts any M4-style adjustable carbine buttstock. As long as your stock is designed for mil-spec tubes, it will fit.
NiB-X nickel boron coating is significantly harder and more corrosion-resistant than standard hard-anodize or phosphate finishes. It's slicker, which means smoother operation, and it holds up better in wet, salty, or dusty environments with less maintenance.
This tube supports six adjustment positions for M4-style collapsible buttstocks, giving you flexibility to dial in length of pull.
Yes. This tube is mil-spec carbine diameter and threading, making it a standard replacement for any AR-platform rifle designed for a carbine buffer tube.

SKU: 194201492 • Width: 3.75in • Height: 1.25in • Depth: 8.5in • Weight: 3oz





Availability: In Stock
The WMD buffer tube carbine NIB-X silver is a mil-spec receiver extension built for AR-platform rifles that need a durable, corrosion-resistant foundation for a collapsible buttstock. WMD Guns machines these tubes from 7075 aluminum extrusion and applies a NiB-X nickel boron coating—a hard, slick finish that stands up to salt, sweat, and harsh field conditions far better than bare aluminum or standard hard-anodize. If you're building or upgrading a carbine and want a buffer tube that won't wear, pit, or require constant maintenance, this is the kind of component that pays for itself in years of worry-free use.
The tube accepts M4-style adjustable carbine buttstocks and offers six adjustment positions, giving you the flexibility to dial in length of pull for different shooting scenarios, clothing layers, or simply dialing it to what feels right behind your gun. The mil-spec diameter and threading are standard across the AR platform, so compatibility isn't a mystery—if your stock is M4-compatible, it'll fit. The silver finish isn't just aesthetics; that NiB-X coating is genuinely harder and more slippery than conventional mil-spec finishes, which means smoother action, easier cleaning, and real corrosion resistance if you're shooting in humid, dusty, or coastal environments.
Whether you're assembling a duty rifle, a precision build, or simply replacing a worn tube on a well-used carbine, WMD's approach here—high-strength alloy, purpose-engineered coating, and tight mil-spec tolerances—means this isn't a throwaway part. It's the kind of detail that separates a rifle you'll trust from one you'll second-guess.
| Material | 7075 Aluminum |
| Finish | NiB-X Nickel Boron (Silver) |
| Tube Type | Mil-Spec Carbine Buffer Tube |
| Buttstock Compatibility | M4-Style Adjustable Carbine (6 positions) |
| Brand | WMD Guns |
Yes. This is a mil-spec carbine receiver extension, and it accepts any M4-style adjustable carbine buttstock. As long as your stock is designed for mil-spec tubes, it will fit.
NiB-X nickel boron coating is significantly harder and more corrosion-resistant than standard hard-anodize or phosphate finishes. It's slicker, which means smoother operation, and it holds up better in wet, salty, or dusty environments with less maintenance.
This tube supports six adjustment positions for M4-style collapsible buttstocks, giving you flexibility to dial in length of pull.
Yes. This tube is mil-spec carbine diameter and threading, making it a standard replacement for any AR-platform rifle designed for a carbine buffer tube.
SKU: 194201492 • Width: 3.75in • Height: 1.25in • Depth: 8.5in • Weight: 3oz
