Brownells194200135
Brownells Ar-15/A1 5.56Mm 20'' 1-7 Twist Rifle Barrel Assembly$278.99
Availability: In Stock
Current Stock: Out of stock
The Brownells AR-15/A1 5.56mm 20" 1-12 twist rifle barrel assembly is built for shooters who want authentic M16A1 profile performance or a lightweight barrel for any AR-15 build. This is a true "skinny" barrel—the exterior contours replicate the original M16A1 geometry, making it ideal if you're after retro aesthetics or simply need a barrel that keeps weight down without sacrificing strength. Machined from 4150 chrome-moly steel and chrome-lined for durability, it arrives with a pre-installed rifle-length barrel extension and comes ready for assembly or stripped depending on your build preference.
The 5.56 NATO chamber accepts both 5.56x45 and .223 Remington ammunition, with a 1-12" twist rate that handles heavier bullets effectively. The muzzle is threaded at ½"-28 TPI, giving you flexibility for suppressors, muzzle brakes, or flash hiders. Matte black phosphate finish protects the steel while keeping the classic look. Every barrel is magnetic particle inspected at the factory to catch any internal flaws before they reach you—critical QC for a component that bears the pressure and precision demands of accurate fire.
A few things to note: this assembly requires a rifle-length gas tube to function (not included), so factor that into your build plan. The 20" length and slim profile make it a natural choice for retro AR builds, hunting rifles, or anyone who values a handy, balanced platform over maximum sight radius.
| Caliber | 5.56 NATO / .223 Rem |
| Barrel Length | 20" |
| Twist Rate | 1-12" |
| Material | 4150 Chrome-Moly Steel |
| Bore Treatment | Chrome-lined |
| Muzzle Thread | ½"-28 TPI |
| Barrel Extension | Rifle-length, pre-installed |
| Finish | Matte Black Phosphate |
| Gas System | Rifle-length (tube sold separately) |
This barrel is configured for a rifle-length gas system. You'll need to source a rifle-length gas tube separately to complete your build.
Yes—the exterior profile is designed to replicate the original M16A1 "skinny" barrel contours, making it ideal for retro AR builds that capture that classic look.
The 5.56 NATO chamber accepts both 5.56x45 NATO and .223 Remington ammunition. The 1-12" twist is optimized for heavier bullets in both calibers.
This is available as either a stripped barrel or a complete assembly. The complete assembly option includes the pre-installed rifle-length barrel extension; either way, you'll still need to source and install a rifle-length gas tube for your build.
SKU: 194200136 • Weight: 2.3oz
Availability: In Stock
Current Stock: Out of stock
The Brownells AR-15/A1 5.56mm 20" 1-12 twist rifle barrel assembly is built for shooters who want authentic M16A1 profile performance or a lightweight barrel for any AR-15 build. This is a true "skinny" barrel—the exterior contours replicate the original M16A1 geometry, making it ideal if you're after retro aesthetics or simply need a barrel that keeps weight down without sacrificing strength. Machined from 4150 chrome-moly steel and chrome-lined for durability, it arrives with a pre-installed rifle-length barrel extension and comes ready for assembly or stripped depending on your build preference.
The 5.56 NATO chamber accepts both 5.56x45 and .223 Remington ammunition, with a 1-12" twist rate that handles heavier bullets effectively. The muzzle is threaded at ½"-28 TPI, giving you flexibility for suppressors, muzzle brakes, or flash hiders. Matte black phosphate finish protects the steel while keeping the classic look. Every barrel is magnetic particle inspected at the factory to catch any internal flaws before they reach you—critical QC for a component that bears the pressure and precision demands of accurate fire.
A few things to note: this assembly requires a rifle-length gas tube to function (not included), so factor that into your build plan. The 20" length and slim profile make it a natural choice for retro AR builds, hunting rifles, or anyone who values a handy, balanced platform over maximum sight radius.
| Caliber | 5.56 NATO / .223 Rem |
| Barrel Length | 20" |
| Twist Rate | 1-12" |
| Material | 4150 Chrome-Moly Steel |
| Bore Treatment | Chrome-lined |
| Muzzle Thread | ½"-28 TPI |
| Barrel Extension | Rifle-length, pre-installed |
| Finish | Matte Black Phosphate |
| Gas System | Rifle-length (tube sold separately) |
This barrel is configured for a rifle-length gas system. You'll need to source a rifle-length gas tube separately to complete your build.
Yes—the exterior profile is designed to replicate the original M16A1 "skinny" barrel contours, making it ideal for retro AR builds that capture that classic look.
The 5.56 NATO chamber accepts both 5.56x45 NATO and .223 Remington ammunition. The 1-12" twist is optimized for heavier bullets in both calibers.
This is available as either a stripped barrel or a complete assembly. The complete assembly option includes the pre-installed rifle-length barrel extension; either way, you'll still need to source and install a rifle-length gas tube for your build.
SKU: 194200136 • Weight: 2.3oz