AeroPrecision167529632
M4E1 5.56 Nato Assem Uppr Rcvr M4 16'' Bbl Carbine Black$619.80
Availability: In Stock
Current Stock: Out of stock
The Precision Reflex Mk12 Mod-H .223/5.56 complete upper receiver is a field-proven, ready-to-run upper assembly built on a forged 7075 aluminum receiver with hard-coat anodizing for durability. This 16-inch barreled upper comes fully assembled, cleaned, and tested—no guesswork, no assembly line shortcuts. It's designed for shooters who want a compact, accurate .223/5.56 platform that doesn't compromise on capability, whether you're running drills at the range, working from a recce position, or building a versatile carbine for duty or sport.
The barrel is Douglas 416 stainless steel with a 1:7 twist and M4 feed ramps, delivering the accuracy and reliability that separates a kit gun from a real tool. A low-profile gas block with dual set screws secures the forearm without fuss, while the rifle-length rail system and dedicated recce top rail give you two levels of mounting real estate—purpose-built for pairing a primary optic with night vision or thermal up front. The included Gas Buster charging handle with military-profile latch cycles smoothly under load, and the muzzle brake (1/2 x 28 threaded) is pinned and collared for permanence.
Every upper includes a bolt carrier group, rail-mounted flip-up front and rear sights, and a matched brake/collar combo, so you're not hunting for random parts. The black finish is clean and professional. At 25 inches overall and 5.7 pounds, this upper is nimble enough for field work without feeling toy-like. Whether you're updating an existing lower or starting a fresh build, this is a no-nonsense upper that shows its work.
| Caliber | .223 / 5.56 NATO |
| Barrel Length | 16 inches |
| Barrel Material & Twist | Douglas 416 stainless steel, 1:7 twist, M4 feed ramps |
| Upper Receiver | Forged T6 7075 aluminum, hard-coat anodized |
| Gas Block | Low-profile with dual set screws |
| Forearm | Rifle length, rail system with recce top rail |
| Charging Handle | Gas Buster with military large latch |
| Sights | Rail-mounted flip-up front and rear |
| Muzzle Device | 1/2 x 28 threaded AE brake and collar |
| Overall Length | 25 inches |
| Weight | 5.7 pounds |
| Included | Bolt carrier group, sights, muzzle brake |
This is a .223/5.56 AR-15 pattern complete upper receiver. It will mate with any standard AR-15 lower receiver. The upper alone does not include a lower—you'll need to source one separately or pair it with an existing lower you own.
Yes. Every upper is factory assembled, cleaned, and tested before shipment. It includes a bolt carrier group, so you only need to attach it to a compatible AR-15 lower and you're ready to run.
The upper receiver assembly includes the complete barreled receiver, bolt carrier group, Gas Buster charging handle, rail-mounted flip-up front and rear sights, and the pinned/collared AE muzzle brake with collar.
Yes. The dual-level rail system is specifically designed for this: the recce top rail and rifle-length forearm rail give you two mounting planes to position a primary optic with night vision or thermal mounted in front of it.
SKU: 197561654 • Weight: 5.7oz
Availability: In Stock
Current Stock: Out of stock
The Precision Reflex Mk12 Mod-H .223/5.56 complete upper receiver is a field-proven, ready-to-run upper assembly built on a forged 7075 aluminum receiver with hard-coat anodizing for durability. This 16-inch barreled upper comes fully assembled, cleaned, and tested—no guesswork, no assembly line shortcuts. It's designed for shooters who want a compact, accurate .223/5.56 platform that doesn't compromise on capability, whether you're running drills at the range, working from a recce position, or building a versatile carbine for duty or sport.
The barrel is Douglas 416 stainless steel with a 1:7 twist and M4 feed ramps, delivering the accuracy and reliability that separates a kit gun from a real tool. A low-profile gas block with dual set screws secures the forearm without fuss, while the rifle-length rail system and dedicated recce top rail give you two levels of mounting real estate—purpose-built for pairing a primary optic with night vision or thermal up front. The included Gas Buster charging handle with military-profile latch cycles smoothly under load, and the muzzle brake (1/2 x 28 threaded) is pinned and collared for permanence.
Every upper includes a bolt carrier group, rail-mounted flip-up front and rear sights, and a matched brake/collar combo, so you're not hunting for random parts. The black finish is clean and professional. At 25 inches overall and 5.7 pounds, this upper is nimble enough for field work without feeling toy-like. Whether you're updating an existing lower or starting a fresh build, this is a no-nonsense upper that shows its work.
| Caliber | .223 / 5.56 NATO |
| Barrel Length | 16 inches |
| Barrel Material & Twist | Douglas 416 stainless steel, 1:7 twist, M4 feed ramps |
| Upper Receiver | Forged T6 7075 aluminum, hard-coat anodized |
| Gas Block | Low-profile with dual set screws |
| Forearm | Rifle length, rail system with recce top rail |
| Charging Handle | Gas Buster with military large latch |
| Sights | Rail-mounted flip-up front and rear |
| Muzzle Device | 1/2 x 28 threaded AE brake and collar |
| Overall Length | 25 inches |
| Weight | 5.7 pounds |
| Included | Bolt carrier group, sights, muzzle brake |
This is a .223/5.56 AR-15 pattern complete upper receiver. It will mate with any standard AR-15 lower receiver. The upper alone does not include a lower—you'll need to source one separately or pair it with an existing lower you own.
Yes. Every upper is factory assembled, cleaned, and tested before shipment. It includes a bolt carrier group, so you only need to attach it to a compatible AR-15 lower and you're ready to run.
The upper receiver assembly includes the complete barreled receiver, bolt carrier group, Gas Buster charging handle, rail-mounted flip-up front and rear sights, and the pinned/collared AE muzzle brake with collar.
Yes. The dual-level rail system is specifically designed for this: the recce top rail and rifle-length forearm rail give you two mounting planes to position a primary optic with night vision or thermal mounted in front of it.
SKU: 197561654 • Weight: 5.7oz