$445.88
Availability: In Stock
Current Stock: Out of stock
The Aero Precision Complete Upper Receiver 5.56 NATO 20" A2 Barrel is a no-nonsense, rifle-length upper built on the same platform Aero uses in their M16A4 Special Edition complete rifles. If you're assembling an AR-15 from the ground up or swapping uppers, this gives you a proven, mil-spec-style upper receiver paired with a 20-inch barrel and classic A2 sights—all you need to mount onto a lower receiver and add a bolt carrier group and charging handle to get running.
The 20-inch barrel is 5.56 NATO chambered with a 1:7 twist rate, built from 4150 chrome moly vanadium and finished with Aero's QPQ corrosion-resistant treatment. That barrel length and twist rate make this upper naturally suited to full-power rifle cartridges and heavier projectiles across the 5.56 spectrum, whether you're reaching out to distance or running drills at the range. The rifle-length gas system keeps recoil manageable and is a proven design that favors reliability over firerate.
You get the full A2 furniture package: detachable carry handle, A2 front sight block with bayonet lug, and A2-pattern handguard. It's traditional AR ergonomics—not flashy, not modular, just honest iron sights and a profile that's been trusted for decades. Muzzle is fitted with a standard A2 flash hider. Keep in mind this is an upper receiver assembly only; you'll need to source a bolt carrier group and charging handle separately, plus a stripped lower to complete the rifle.
Build quality from Aero Precision is straightforward and held to spec. This upper works well for hunters, long-range shooters, and anyone who values simplicity and durability over modularity.
| Caliber | 5.56 NATO |
| Barrel Length | 20 inches |
| Barrel Twist | 1:7 |
| Barrel Material | 4150 Chrome Moly Vanadium |
| Barrel Finish | QPQ Corrosion Resistant |
| Gas System | Rifle Length |
| Receiver | Standard M4 Upper Receiver |
| Handguard | A2 Style, Rifle Length |
| Front Sight | A2 Front Sight Block with Bayonet Lug |
| Rear Sight | A2 Detachable Carry Handle |
| Muzzle Device | Standard A2 Flash Hider |
| Finish | Black |
The bolt carrier group (BCG) and charging handle are not included. You'll need to purchase those separately, as well as a stripped lower receiver to complete your rifle.
This is a standard M4 upper receiver and will work with any AR-15 lower receiver designed for 5.56 NATO or .223 Remington.
The 20-inch barrel with a 1:7 twist rate is well-suited to distance work, especially with heavier 5.56 projectiles. The rifle-length gas system provides reliable cycling and manageable recoil for accuracy-focused shooting.
The front sight block is pinned. We don't have details on removal or replacement compatibility, so contact Aero Precision directly if you're planning modifications.
SKU: 115666444 • Width: 4in • Height: 4in • Depth: 37.5in • Weight: 5.31oz
Availability: In Stock
Current Stock: Out of stock
The Aero Precision Complete Upper Receiver 5.56 NATO 20" A2 Barrel is a no-nonsense, rifle-length upper built on the same platform Aero uses in their M16A4 Special Edition complete rifles. If you're assembling an AR-15 from the ground up or swapping uppers, this gives you a proven, mil-spec-style upper receiver paired with a 20-inch barrel and classic A2 sights—all you need to mount onto a lower receiver and add a bolt carrier group and charging handle to get running.
The 20-inch barrel is 5.56 NATO chambered with a 1:7 twist rate, built from 4150 chrome moly vanadium and finished with Aero's QPQ corrosion-resistant treatment. That barrel length and twist rate make this upper naturally suited to full-power rifle cartridges and heavier projectiles across the 5.56 spectrum, whether you're reaching out to distance or running drills at the range. The rifle-length gas system keeps recoil manageable and is a proven design that favors reliability over firerate.
You get the full A2 furniture package: detachable carry handle, A2 front sight block with bayonet lug, and A2-pattern handguard. It's traditional AR ergonomics—not flashy, not modular, just honest iron sights and a profile that's been trusted for decades. Muzzle is fitted with a standard A2 flash hider. Keep in mind this is an upper receiver assembly only; you'll need to source a bolt carrier group and charging handle separately, plus a stripped lower to complete the rifle.
Build quality from Aero Precision is straightforward and held to spec. This upper works well for hunters, long-range shooters, and anyone who values simplicity and durability over modularity.
| Caliber | 5.56 NATO |
| Barrel Length | 20 inches |
| Barrel Twist | 1:7 |
| Barrel Material | 4150 Chrome Moly Vanadium |
| Barrel Finish | QPQ Corrosion Resistant |
| Gas System | Rifle Length |
| Receiver | Standard M4 Upper Receiver |
| Handguard | A2 Style, Rifle Length |
| Front Sight | A2 Front Sight Block with Bayonet Lug |
| Rear Sight | A2 Detachable Carry Handle |
| Muzzle Device | Standard A2 Flash Hider |
| Finish | Black |
The bolt carrier group (BCG) and charging handle are not included. You'll need to purchase those separately, as well as a stripped lower receiver to complete your rifle.
This is a standard M4 upper receiver and will work with any AR-15 lower receiver designed for 5.56 NATO or .223 Remington.
The 20-inch barrel with a 1:7 twist rate is well-suited to distance work, especially with heavier 5.56 projectiles. The rifle-length gas system provides reliable cycling and manageable recoil for accuracy-focused shooting.
The front sight block is pinned. We don't have details on removal or replacement compatibility, so contact Aero Precision directly if you're planning modifications.
SKU: 115666444 • Width: 4in • Height: 4in • Depth: 37.5in • Weight: 5.31oz