Brownells194200136
Brownells Ar-15/A1 5.56Mm 20'' 1-12 Twist Rifle Barrel Assembly$247.99
Availability: In Stock
Current Stock: Out of stock
The Brownells AR-15/A1 5.56mm 20" 1-7 twist rifle barrel assembly is a purpose-built retro rifle length setup for builders and shooters who want to run authentic A1-style AR-15 builds or just prefer the original platform. This is a complete barrel assembly—not just a tube—so you get everything needed to install it on a stripped upper receiver: the barrel itself, front sight base, gas tube extension, sight post, detent and spring, sling swivel, rivet, delta ring, barrel nut, weld spring, snap ring, and triangular handguard cap. If you're going classic or restoring a rifle to original specs, the legwork is already done.
The barrel is chrome-lined 4150 steel, chambered in 5.56x45 NATO with a 1-7 twist rate that stabilizes the full range of 5.56 loads and heavier bullets. The 20" length is rifle-length gas system spec, and muzzle threads are 1/2-28 for standard A1-style muzzle brakes or flash hiders. Black phosphate finish resists corrosion and matches the retro aesthetic. The .625" No F Marks sight base is correct for A1 uppers and accepts standard AR-15 front sight posts.
This assembly is ideal for retro builds, clones, or shooters who simply prefer the original AR-15 platform for hunting, range work, or general shooting. Because the barrel comes pre-assembled with the extension, front sight, and hardware, you skip the headaches of sourcing compatible parts individually and get a rifle-length setup that's ready to go.
| Caliber | 5.56x45 NATO |
| Barrel Length | 20" |
| Twist Rate | 1-7 |
| Barrel Steel | 4150 Chrome-Lined |
| Muzzle Thread | 1/2-28 |
| Gas System | Rifle-Length |
| Finish | Black Phosphate |
| Sight Base Marking | .625 No F Marks |
| Includes | Front sight base, gas tube extension, sight post, detent, spring, sling swivel, rivet, delta ring, barrel nut, weld spring, snap ring, triangular handguard cap |
Yes, this is a standard rifle-length barrel assembly designed for AR-15 A1 uppers. It installs directly into a compatible upper receiver with the barrel nut and all included hardware.
The 1-7 twist rate is suitable for the full range of 5.56x45 NATO ammunition, including standard 55-grain loads and heavier bullet weights.
This is a complete barrel assembly. It includes the barrel, front sight base, gas tube extension, delta ring, handguard cap, barrel nut, and all necessary springs, detents, and hardware. You only need a stripped upper receiver to install it.
The 1/2-28 muzzle threads are the original A1 standard. You can use any muzzle device threaded for 1/2-28, though the retro configuration is most authentic with period-correct A1-style flash hiders or brakes.
SKU: 194200135 • Weight: 2.31oz
Availability: In Stock
Current Stock: Out of stock
The Brownells AR-15/A1 5.56mm 20" 1-7 twist rifle barrel assembly is a purpose-built retro rifle length setup for builders and shooters who want to run authentic A1-style AR-15 builds or just prefer the original platform. This is a complete barrel assembly—not just a tube—so you get everything needed to install it on a stripped upper receiver: the barrel itself, front sight base, gas tube extension, sight post, detent and spring, sling swivel, rivet, delta ring, barrel nut, weld spring, snap ring, and triangular handguard cap. If you're going classic or restoring a rifle to original specs, the legwork is already done.
The barrel is chrome-lined 4150 steel, chambered in 5.56x45 NATO with a 1-7 twist rate that stabilizes the full range of 5.56 loads and heavier bullets. The 20" length is rifle-length gas system spec, and muzzle threads are 1/2-28 for standard A1-style muzzle brakes or flash hiders. Black phosphate finish resists corrosion and matches the retro aesthetic. The .625" No F Marks sight base is correct for A1 uppers and accepts standard AR-15 front sight posts.
This assembly is ideal for retro builds, clones, or shooters who simply prefer the original AR-15 platform for hunting, range work, or general shooting. Because the barrel comes pre-assembled with the extension, front sight, and hardware, you skip the headaches of sourcing compatible parts individually and get a rifle-length setup that's ready to go.
| Caliber | 5.56x45 NATO |
| Barrel Length | 20" |
| Twist Rate | 1-7 |
| Barrel Steel | 4150 Chrome-Lined |
| Muzzle Thread | 1/2-28 |
| Gas System | Rifle-Length |
| Finish | Black Phosphate |
| Sight Base Marking | .625 No F Marks |
| Includes | Front sight base, gas tube extension, sight post, detent, spring, sling swivel, rivet, delta ring, barrel nut, weld spring, snap ring, triangular handguard cap |
Yes, this is a standard rifle-length barrel assembly designed for AR-15 A1 uppers. It installs directly into a compatible upper receiver with the barrel nut and all included hardware.
The 1-7 twist rate is suitable for the full range of 5.56x45 NATO ammunition, including standard 55-grain loads and heavier bullet weights.
This is a complete barrel assembly. It includes the barrel, front sight base, gas tube extension, delta ring, handguard cap, barrel nut, and all necessary springs, detents, and hardware. You only need a stripped upper receiver to install it.
The 1/2-28 muzzle threads are the original A1 standard. You can use any muzzle device threaded for 1/2-28, though the retro configuration is most authentic with period-correct A1-style flash hiders or brakes.
SKU: 194200135 • Weight: 2.31oz