B
Brownells194200186
Brownells Brn-4 Assembled Upper 13.7'' Medium Chrome Lined Barrel Black$1,249.99
Availability: In Stock
Current Stock: Out of stock
The Brownells BRN-4 Assembled Upper is a complete, ready-to-run upper receiver assembly built for shooters who want quality AR-15 components without the guesswork. This 16-inch medium profile upper arrives fully assembled with barrel and gas system installed—just add your HK 416-compatible handguard and a 1/2-28 muzzle device, then you're running. It's purpose-built for hunters, competition shooters, and serious recreational marksmen who value durability and reliability over cutting corners.
The heart of the BRN-4 is a chrome-lined, 4150 chrome moly barrel button-rifled by Faxon with a 1-7 twist rate capable of stabilizing heavier projectiles. Chrome-lined barrels have been the standard for hard-use rifles for decades because they resist fouling, extend barrel life, and handle sustained fire without degradation. The matte black phosphate finish provides corrosion resistance and a clean, professional appearance. The barrel nut uses an extended thread design that engages the barrel extension over significantly more surface area than a standard AR-15, delivering a rock-solid, rigid mount—critical for accuracy and reliability.
Inside, you'll find a purpose-built bolt carrier group machined from forged 8620 steel with a chrome bolt precision-machined from 9310 tool steel. The bolt is headspaced before and after barrel installation to guarantee consistent chamber dimensions. The upper receiver itself is machined from billet aluminum to replicate forged upper profiles, finished in hard coat anodizing. A vented gas block reduces rearward gas bleed into the system, and a Magpul ejection port cover plus mil-spec charging handle come standard. Every BRN-4 is test-fired before shipping, so minor brass marks or light fouling in the chamber are normal signs of a quality check.
Assembly is straightforward: handguard slides onto the barrel with a single retention bolt, and any AR-15-pattern 1/2-28 muzzle device threads on without special tools. Brownells recommends an H1 or H2 buffer tube with a carbine spring for optimal cycling, and use of 5.56×45mm NATO ammunition.
| Barrel Length | 16 inches | |
| Barrel Profile | Medium | |
| Barrel Material | 4150 Chrome Moly, Chrome-Lined | |
| Barrel Rifling Twist | 1:7 | |
| Muzzle Threads | 1/2-28 | |
| Upper Receiver Material | Billet Aluminum | |
| Upper Receiver Finish | Hard Coat Anodize | |
| Bolt Carrier Group Material | Forged 8620 Steel Carrier, 9310 Tool Steel Bolt | |
| Bolt Carrier Finish | Phosphate | |
| Exterior Finish | Matte Black Phosphate | |
| Handguard Compatibility | HK 416-Pattern | |
| Included Accessories | Magpul Ejection Port Cover, Mil-Spec Charging Handle | |
| Manufacturer | Brownells |
The upper accepts any HK 416-compatible handguard, which slides onto the barrel and secures with a single bolt for tool-free installation. Any AR-15-pattern muzzle device with 1/2-28 threads will fit; no special tools or adapters are needed.
Yes, the BRN-4 is designed to fit standard AR-15 lower receivers.
The upper arrives with the barrel and gas system installed and test-fired. You'll need to add a handguard, a 1/2-28 muzzle device, and a lower receiver to complete the rifle. Brownells recommends pairing it with an H1 or H2 buffer tube and carbine spring for optimal operation.
Brownells recommends using newly manufactured, quality 5.56×45mm NATO ammunition for optimal operation.
SKU: 194200199 • Weight: 5oz
Availability: In Stock
Current Stock: Out of stock
The Brownells BRN-4 Assembled Upper is a complete, ready-to-run upper receiver assembly built for shooters who want quality AR-15 components without the guesswork. This 16-inch medium profile upper arrives fully assembled with barrel and gas system installed—just add your HK 416-compatible handguard and a 1/2-28 muzzle device, then you're running. It's purpose-built for hunters, competition shooters, and serious recreational marksmen who value durability and reliability over cutting corners.
The heart of the BRN-4 is a chrome-lined, 4150 chrome moly barrel button-rifled by Faxon with a 1-7 twist rate capable of stabilizing heavier projectiles. Chrome-lined barrels have been the standard for hard-use rifles for decades because they resist fouling, extend barrel life, and handle sustained fire without degradation. The matte black phosphate finish provides corrosion resistance and a clean, professional appearance. The barrel nut uses an extended thread design that engages the barrel extension over significantly more surface area than a standard AR-15, delivering a rock-solid, rigid mount—critical for accuracy and reliability.
Inside, you'll find a purpose-built bolt carrier group machined from forged 8620 steel with a chrome bolt precision-machined from 9310 tool steel. The bolt is headspaced before and after barrel installation to guarantee consistent chamber dimensions. The upper receiver itself is machined from billet aluminum to replicate forged upper profiles, finished in hard coat anodizing. A vented gas block reduces rearward gas bleed into the system, and a Magpul ejection port cover plus mil-spec charging handle come standard. Every BRN-4 is test-fired before shipping, so minor brass marks or light fouling in the chamber are normal signs of a quality check.
Assembly is straightforward: handguard slides onto the barrel with a single retention bolt, and any AR-15-pattern 1/2-28 muzzle device threads on without special tools. Brownells recommends an H1 or H2 buffer tube with a carbine spring for optimal cycling, and use of 5.56×45mm NATO ammunition.
| Barrel Length | 16 inches | |
| Barrel Profile | Medium | |
| Barrel Material | 4150 Chrome Moly, Chrome-Lined | |
| Barrel Rifling Twist | 1:7 | |
| Muzzle Threads | 1/2-28 | |
| Upper Receiver Material | Billet Aluminum | |
| Upper Receiver Finish | Hard Coat Anodize | |
| Bolt Carrier Group Material | Forged 8620 Steel Carrier, 9310 Tool Steel Bolt | |
| Bolt Carrier Finish | Phosphate | |
| Exterior Finish | Matte Black Phosphate | |
| Handguard Compatibility | HK 416-Pattern | |
| Included Accessories | Magpul Ejection Port Cover, Mil-Spec Charging Handle | |
| Manufacturer | Brownells |
The upper accepts any HK 416-compatible handguard, which slides onto the barrel and secures with a single bolt for tool-free installation. Any AR-15-pattern muzzle device with 1/2-28 threads will fit; no special tools or adapters are needed.
Yes, the BRN-4 is designed to fit standard AR-15 lower receivers.
The upper arrives with the barrel and gas system installed and test-fired. You'll need to add a handguard, a 1/2-28 muzzle device, and a lower receiver to complete the rifle. Brownells recommends pairing it with an H1 or H2 buffer tube and carbine spring for optimal operation.
Brownells recommends using newly manufactured, quality 5.56×45mm NATO ammunition for optimal operation.
SKU: 194200199 • Weight: 5oz